UPDATE:
I cleaned out some old patches form config.plist
Now my machine is booting without an invalid ig-plattform-id and I get 1536 MB of VRAM
Sadly the glitches are still in places
The only thing I noticed so far, I can't "fast forward" (set the cursor to a position) youtube videos in Safari, they will freeze at the new point, In chrome this problem doesn't exist...
Installed LILU.kext to /L/E, no changes for youtube videos
UPDATE: LILU.kext was old
Now everything works great!
Thanks
Off topic: Did the audio trick as well..
There's no problem anymore! I used an old version of lily.kext
I updated it and everything works great!