So, you removed the shaders and/or the Prepar3d.cfg file and, guess what, both the sim and GSX are now working ? So much for all the "it's caused by GSX" drama...next time, please trust me and follow my suggestions.
Anyway, if you fixed it by removing the Prepar3d.cfg file, is normal you graphics might look worse now, because it has reverted all your settings to a default reasonable for your hardware. You probably have your settings much higher before, which would of course increase the quality, but it will also require more VRAM.
So, go through your settings, one by one, and see how much you can improve the quality, without crashing your system. I think your previous crashes were caused by VRAM exhaustion, not normal RAM (which is almost impossible in 64 bit)