That sounds excellent Dogscoff, but how big a project would it be to do all that? Would it require hard code changes or could it be done with the text files? I only bought the game a few months back so I'm still in playing mode. Looking forward to getting my hands dirty with some modding shortly.
I'm currently playing a Large Universe game with all Rock/Oxygen breathing races, restricting colonisation to Home Planet Type and Breathable Atmosphere. Plus I have removed Gas Giant and Ice Planet Colonisers from the Research Tree. With Finite Resources it makes an interesting game. Very few planets are available and each one is vitally important.
Unfortunately, the AI doesn't seem to be handling the restrictions too well

Love to play a PBEM game like this though.