Ingame update, tremendously much better than the original post, still contains some performance issues.
Used Accurate GETLLAR to tremendously reduce random crashes. Use CPU Blit to improve performance and better upscaling. I recommend threshold 512x512, the outline of objects will look rectangles. MLAA Patch is available on the wiki to improve performance. (Used in this report)
I recommend framelimiter on Auto. The game is tied to the framerate, 30fps is the frame target. Pause menu goes too fast at uncapped fps, frame target for it is 60.
Performance is pretty alright on my system but, it still can go as low as 20fps, I expect weaker systems to be much worse.