Maniacal
the green Napoleon
You're not allowed to share certain files like the main .jar ones (or used to not be able to) and aren't allowed to sell mods, but there is nothing illegal about modding games otherwise.
Pretty much. The lighting should be in shades and stuff, but there's an issue where it's just black in some spots.
I wish there was a tekkit pack for the most recent patch. We are still using 1.2 or something, none of the recent patches from Mojang are incorporated.
This will take a while, imho, because each mod will have to be compatible with multiplayer due to the ability to make your single player game into a LAN server.