Use vsync if all else fails. Good rule of thumb.
The custom_e.exe's should be pretty straight forward. They're only a few modifications to the game, because every computer will handle stuff differently.
Shoot the Bullet should be something like 32-bit for screen mode, and full for rendering rate. If you use vsync, check the don't use vertical sync box, that way vsync can overwrite it.
For SA onward, color mode should be 32-bit and no frameskip. The input latency should be automatic. If you use the vsync patch, it has to be set to fast, or else vsync won't do a thing.
Get vsync
here, courtesy of Drake. This has vsync for every danmaku Touhou, including UFO. It doesn't have Double Spoiler or Great Fairy Wars yet (obviously not Ten Desires) because those are still being tested, if memory serves.
If vsync fails, try changing the rendering rate in the config, then use vsync again. (You have to use vsync every time you want to play the games btw) Your computer might not be powerful enough to play these games at full force, which may be why you're having framerate issues.
Hope this helps!
