1. - Is there any way to turn off the asteroid field lines? By mid to late game, I have so many asteroid lines crossing the galaxy is just becomes a bit annoying. I didn't see an option to turn them on or off in the options menu.
2. - Can we disable the "Victory Certain/Defeat Likely"? Personally I'd rather be taking a chance on attacking an enemy fleet rather than being told if I'll win or lose before hand.
I believe you can disable the lines, but it will apply to all lines, such as trade routes, and not just asteroid lines. Check game settings. I think it is under graphical.
No way to disable battle prediction AFAIK.