I'm no expert, but I will try to answer your questions.
1) Yes, tons of ways, I not sure if the have Mods for diplomacy on that website, but you can find some in the forums.
2) As far as I know, you have to have it so everything is connected.
Example
Ship needs to but in a race, with ablities linked, mesh files and etc.
Abilites need to be connected to a ship, with a buff file created and etc.