Ok so somehow I made it work by setting every setting to the lowest point or off, starting up two or three times and there we go.
After it worked I set every single option to the highest possible point and I got around 150 FPS, fluctuating to around a 100 FPS under heavy load.
So I though everything was fine and merry, until I decided to restart Minecraft to see if it works.
Nope, epic start world loading crash again (probably too much load or something?) unfortunately.
It's weird since it's only on startup, I had flown around the world on max settings and it loaded just fine.
...a long time ago
there had been flickering-screen-errors occured, if you haven´t deaktivated Threaded Optimazation. But since some versions of optifine there are no errors anymore. So this info isn´t actual anymore? Or does the performace get better, if i deaktivate the Threaded Optimazation? Its very annoying to disable it all the time only for minecraft. So it there is no screen-flickering i do NOT have to deaktive thredded optimazations?
I still get flickering if I don't disable threaded optimization, latest nVidia drivers, GeForce 650m