diff --git a/qubes/__init__.py b/qubes/__init__.py
index 9ce60735..b8f4fa5f 100644
--- a/qubes/__init__.py
+++ b/qubes/__init__.py
@@ -485,7 +485,7 @@ class VMCollection(object):
 
 
     def get_vms_connected_to(self, netvm):
-        new_vms = set([netvm])
+        new_vms = set([self[netvm]])
         dependent_vms = set()
 
         # Dependency resolving only makes sense on NetVM (or derivative)
@@ -962,7 +962,7 @@ class PropertyHolder(qubes.events.Emitter):
         for prop in self.proplist():
             try:
                 # pylint: disable=protected-access
-                self._init_property(self, prop, getattr(src, prop._attr_name))
+                self._init_property(prop, getattr(src, prop._attr_name))
             except AttributeError:
                 continue
 
@@ -1211,11 +1211,11 @@ class Qubes(PropertyHolder):
                 self, None, qid=0, name='dom0'))
 
         # stage 3: load global properties
-        self.load_properties(self.xml, load_stage=3)
+        self.load_properties(load_stage=3)
 
         # stage 4: fill all remaining VM properties
         for vm in self.domains:
-            vm.load_properties(None, load_stage=4)
+            vm.load_properties(load_stage=4)
 
         # stage 5: misc fixups
 
@@ -1335,8 +1335,6 @@ class Qubes(PropertyHolder):
         if self.default_template == vm:
             del self.default_template
 
-        return super(QubesVmCollection, self).pop(qid)
-
 
     @qubes.events.handler('property-pre-set:clockvm')
     def on_property_pre_set_clockvm(self, event, name, newvalue, oldvalue=None):
@@ -1349,7 +1347,9 @@ class Qubes(PropertyHolder):
             newvalue.services['ntpd'] = False
 
 
-    @qubes.events.handler('property-pre-set:default_netvm')
+    @qubes.events.handler(
+        'property-pre-set:default_netvm',
+        'property-pre-set:default_fw_netvm')
     def on_property_pre_set_default_netvm(self, event, name, newvalue,
             oldvalue=None):
         # pylint: disable=unused-argument,invalid-name
diff --git a/qubes/dochelpers.py b/qubes/dochelpers.py
index 188e3afc..2120dfb3 100644
--- a/qubes/dochelpers.py
+++ b/qubes/dochelpers.py
@@ -58,7 +58,7 @@ def fetch_ticket_info(uri):
         for row in list(reader)[:2])))
 
 
-def ticket(name, rawtext, text, lineno, inliner, options={}, content=[]):
+def ticket(name, rawtext, text, lineno, inliner, options=None, content=None):
     '''Link to qubes ticket
 
     :param str name: The role name used in the document
@@ -71,6 +71,9 @@ def ticket(name, rawtext, text, lineno, inliner, options={}, content=[]):
     :param content: The directive content for customisation
     ''' # pylint: disable=unused-argument
 
+    if options is None:
+        options = {}
+
     ticketno = text.lstrip('#')
     if not ticket.isdigit():
         msg = inliner.reporter.error(
diff --git a/qubes/events.py b/qubes/events.py
index 236ec9ef..c773f3c7 100644
--- a/qubes/events.py
+++ b/qubes/events.py
@@ -69,7 +69,7 @@ def ishandler(obj):
 class EmitterMeta(type):
     '''Metaclass for :py:class:`Emitter`'''
     def __init__(cls, name, bases, dict_):
-        super(type, cls).__init__(name, bases, dict_)
+        super(EmitterMeta, cls).__init__(name, bases, dict_)
         cls.__handlers__ = collections.defaultdict(set)
 
         try:
diff --git a/qubes/plugins.py b/qubes/plugins.py
index 18e4e98d..618237bf 100644
--- a/qubes/plugins.py
+++ b/qubes/plugins.py
@@ -33,6 +33,7 @@ import os
 class Plugin(type):
     '''Base metaclass for plugins'''
     def __init__(cls, name, bases, dict_):
+        super(Plugin, cls).__init__(name, bases, dict_)
         # pylint: disable=unused-argument
         if hasattr(cls, 'register'):
             cls.register[cls.__name__] = cls
diff --git a/qubes/storage/__init__.py b/qubes/storage/__init__.py
index d889e961..8de21d23 100644
--- a/qubes/storage/__init__.py
+++ b/qubes/storage/__init__.py
@@ -100,7 +100,8 @@ class VMStorage(object):
     def get_config_params(self):
         raise NotImplementedError()
 
-    def _copy_file(self, source, destination):
+    @staticmethod
+    def _copy_file(source, destination):
         '''Effective file copy, preserving sparse files etc.
         '''
         # TODO: Windows support
@@ -142,9 +143,9 @@ class VMStorage(object):
 
         self.vm.log.info('Creating directory: {0}'.format(self.vm.dir_path))
         os.mkdir(self.vmdir)
-        self.create_on_disk_private_img(verbose, source_template)
-        self.create_on_disk_root_img(verbose, source_template)
-        self.reset_volatile_storage(verbose, source_template)
+        self.create_on_disk_private_img(source_template)
+        self.create_on_disk_root_img(source_template)
+        self.reset_volatile_storage(source_template)
 
         os.umask(old_umask)
 
@@ -166,7 +167,8 @@ class VMStorage(object):
             # XXX which modules? -woju
 
 
-    def rename(self, newpath, oldpath):
+    @staticmethod
+    def rename(newpath, oldpath):
         '''Move storage directory, most likely during domain's rename.
 
         .. note::
diff --git a/qubes/tests/__init__.py b/qubes/tests/__init__.py
index 01a94680..bb493f5f 100644
--- a/qubes/tests/__init__.py
+++ b/qubes/tests/__init__.py
@@ -138,7 +138,7 @@ class QubesTestCase(unittest.TestCase):
             self.assertEqual(xml1.get(key), xml2.get(key))
 
 
-    def assertEventFired(self, emitter, event, args=[], kwargs=[]):
+    def assertEventFired(self, emitter, event, args=None, kwargs=None):
         '''Check whether event was fired on given emitter and fail if it did
         not.
 
@@ -154,9 +154,9 @@ class QubesTestCase(unittest.TestCase):
         for ev, ev_args, ev_kwargs in emitter.fired_events:
             if ev != event:
                 continue
-            if any(i not in ev_args for i in args):
+            if args is not None and any(i not in ev_args for i in args):
                 continue
-            if any(i not in ev_kwargs for i in kwargs):
+            if kwargs is not None and any(i not in ev_kwargs for i in kwargs):
                 continue
 
             return
@@ -164,7 +164,7 @@ class QubesTestCase(unittest.TestCase):
         self.fail('event {!r} did not fire on {!r}'.format(event, emitter))
 
 
-    def assertEventNotFired(self, emitter, event, args=[], kwargs=[]):
+    def assertEventNotFired(self, emitter, event, args=None, kwargs=None):
         '''Check whether event was fired on given emitter. Fail if it did.
 
         :param emitter: emitter which is being checked
@@ -179,9 +179,9 @@ class QubesTestCase(unittest.TestCase):
         for ev, ev_args, ev_kwargs in emitter.fired_events:
             if ev != event:
                 continue
-            if any(i not in ev_args for i in args):
+            if args is not None and any(i not in ev_args for i in args):
                 continue
-            if any(i not in ev_kwargs for i in kwargs):
+            if kwargs is not None and any(i not in ev_kwargs for i in kwargs):
                 continue
 
             self.fail('event {!r} did fire on {!r}'.format(event, emitter))
diff --git a/qubes/tests/vm/adminvm.py b/qubes/tests/vm/adminvm.py
index 8bc3e316..655812ba 100644
--- a/qubes/tests/vm/adminvm.py
+++ b/qubes/tests/vm/adminvm.py
@@ -36,12 +36,13 @@ class TestVMM(object):
 
 class TestHost(object):
     # pylint: disable=too-few-public-methods
-    def __init__(self, offline_mode=False):
+    def __init__(self):
         self.memory_total = 1000
 
 # this probably can be shared and not as dummy as is
 class TestApp(qubes.tests.TestEmitter):
     def __init__(self):
+        super(TestApp, self).__init__()
         self.vmm = TestVMM()
         self.host = TestHost()
 
diff --git a/qubes/vm/__init__.py b/qubes/vm/__init__.py
index 3dbabe0f..2301c212 100644
--- a/qubes/vm/__init__.py
+++ b/qubes/vm/__init__.py
@@ -141,21 +141,21 @@ class BaseVM(qubes.PropertyHolder):
 
     __metaclass__ = BaseVMMeta
 
-    def __init__(self, app, xml, load_stage=2, services={}, devices=None,
-            tags={}, *args, **kwargs):
+    def __init__(self, app, xml, services=None, devices=None, tags=None,
+            *args, **kwargs):
         # pylint: disable=redefined-outer-name
         #: mother :py:class:`qubes.Qubes` object
         self.app = app
 
         #: dictionary of services that are run on this domain
-        self.services = services
+        self.services = services or {}
 
         #: :py:class`DeviceManager` object keeping devices that are attached to
         #: this domain
         self.devices = DeviceManager(self) if devices is None else devices
 
         #: user-specified tags
-        self.tags = tags
+        self.tags = tags or {}
 
         self.events_enabled = False
         all_names = set(prop.__name__
@@ -535,7 +535,8 @@ class BaseVM(qubes.PropertyHolder):
     def has_firewall(self):
         return os.path.exists(self.firewall_conf)
 
-    def get_firewall_defaults(self):
+    @staticmethod
+    def get_firewall_defaults():
         return {
             'rules': list(),
             'allow': True,
diff --git a/qubes/vm/qubesvm.py b/qubes/vm/qubesvm.py
index c176f382..0547e67d 100644
--- a/qubes/vm/qubesvm.py
+++ b/qubes/vm/qubesvm.py
@@ -357,7 +357,7 @@ class QubesVM(qubes.vm.BaseVM):
     @property
     def uses_custom_config(self):
         '''True if this machine has config in non-standard place.'''
-        return not self.property_is_default(self, 'conf_file')
+        return not self.property_is_default('conf_file')
 #       return self.conf_file != self.storage.abspath(self.name + '.conf')
 
     @property
@@ -585,7 +585,7 @@ class QubesVM(qubes.vm.BaseVM):
         self.dir_path = self.dir_path.replace(
             '/{}/', '/{}/'.format(old_name, new_name))
 
-        if self.property_is_default(self, 'conf_file'):
+        if self.property_is_default('conf_file'):
             new_conf = os.path.join(
                 self.dir_path, _default_conf_file(self, old_name))
             old_conf = os.path.join(
@@ -746,14 +746,14 @@ class QubesVM(qubes.vm.BaseVM):
 
         if self._start_guid_first and start_guid and not preparing_dvm \
                 and os.path.exists('/var/run/shm.id'):
-            self.start_guid(notify_function=notify_function)
+            self.start_guid()
 
         if not preparing_dvm:
-            self.start_qrexec_daemon(notify_function=notify_function)
+            self.start_qrexec_daemon()
 
         if start_guid and not preparing_dvm \
                 and os.path.exists('/var/run/shm.id'):
-            self.start_guid(notify_function=notify_function)
+            self.start_guid()
 
 
     def shutdown(self):
@@ -881,7 +881,7 @@ class QubesVM(qubes.vm.BaseVM):
 
         if gui and os.getenv("DISPLAY") is not None \
                 and not self.is_guid_running():
-            self.start_guid(verbose=verbose, notify_function=notify_function)
+            self.start_guid()
 
         args = [qubes.config.system_path['qrexec_client_path'],
             '-d', str(self.name),
@@ -957,7 +957,7 @@ class QubesVM(qubes.vm.BaseVM):
 
 
 
-    def start_guid(self, extra_guid_args=[]):
+    def start_guid(self, extra_guid_args=None):
         '''Launch gui daemon.
 
         GUI daemon securely displays windows from domain.
@@ -972,7 +972,8 @@ class QubesVM(qubes.vm.BaseVM):
             '-c', self.label.color,
             '-i', self.label.icon_path,
             '-l', str(self.label.index)]
-        guid_cmd += extra_guid_args
+        if extra_guid_args is not None:
+            guid_cmd += extra_guid_args
 
         if self.debug:
             guid_cmd += ['-v', '-v']
@@ -1059,7 +1060,7 @@ class QubesVM(qubes.vm.BaseVM):
             source_template = self.template
         assert source_template is not None
 
-        self.storage.create_on_disk(verbose, source_template)
+        self.storage.create_on_disk(source_template)
 
         if self.updateable:
             kernels_dir = source_template.kernels_dir