[Nuka1195]

I haven't read this whole thread, but I briefly looked at your code and wondered why you run as a service?

the following test addon.xml and addon.py work fine as a screensaver, though i'm on current git. (nightlies)

PHP Code:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<addon id="screensaver.movie_trailers" name="Movie Trailers Screensaver" version="1.0.0" provider-name="nuka1195">
    <requires>
        <import addon="xbmc.addon" version="12.0.0"/>
        <import addon="xbmc.python" version="2.1.0"/>
    </requires>
    <extension point="xbmc.ui.screensaver" library="addon.py"/>
    <extension point="xbmc.addon.metadata">
        <platform>all</platform>
        <nochangelog>true</nochangelog>
        <nofanart>false</nofanart>
        <noicon>false</noicon>
        <license>Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License</license>
        <website></website>
        <source>https://github.com/nuka1195/screensaver.movie_trailers.git</source>
        <forum></forum>
        <email></email>    
        <summary lang="en">Watch movie trailers as your screensaver.</summary>
        <description lang="en">Watch movie trailers as your screensaver.</description>
        <disclaimer lang="en">This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License *see license.txt</disclaimer>
    </extension>
</addon> 


PHP Code:

#!/usr/bin/python
# -*- coding: UTF-8 -*-
#
## Movie Trailers: Video plugin

# enable this import for debugging
#from resources.lib import pydev_debug
##from resources.lib.addonmodule import XBMCAddon

ADDON_ID = "screensaver.movie_trailers"


if (__name__ == "__main__"):
    # we pass an instance of XBMCAddon() to all modules,
    # XBMCAddon() includes sys.argv items and parsed parameters.
    ##m_addon = XBMCAddon()
    import xbmc
    xbmc.Player().play("/Users/user/Trailers/afterearth-tlr2_h640w-trailer.mov")