What if there is this mod and the author says in the readme.txt that anyone can do anything with it?
And What if I can't find the original author? His emails dont exist anymore?
Also, what if I made a mod, the creation is all mine but someone had the same idea and posted before me?
And last, about icons. I made a mod that chages the icons of the holocrons of both games. I used images I found in the internet. Is there some legal issue in this case?
1) Fair game
2) Out of luck, sorry.
3) Fair game
4) Consensus is still out on this one. If they have a fair use policy on their site, or grant permission it's fair game, otherwise best to avoid it.