1. is it generally just the lag issue on the shader option or are they not working at all?
Regarding the lag (since I can not reproduce it) you probably should try to activate the window mode on the launcher options if not active already (or deactivate it if active) and try again. Also worth checking is pressing alt+enter makes it better. Some feedback about the results would be nice.
2. The lights on the ragnarok have been changed already to smaller versions. The problem in openGL is that instead of using the original textures it uses spheres with the size of the light settings. I already have made suggestions about it to the creator of the openGL renderer but until a new improved version gets released we have to live with it. Strange part is that the image you provided does not look like anything I have seen during my tests, after I did the update to the lights (reduced light sizes).
3. yes, trains and asteroids. It is an issue with the mass of the ships and the force it receives. Dunno yet how to fix it without destroying the heavy ship handling.