re: Copyright:
For what it's worth, a mod author selling their mod is against the TOS, but completely impractical to enforce. Indeed, pretty much everything related to mod copyright, regardless of game, is impractical to enforce. Lost views, downloads, or sales are very unlikely to cause enough financial damage to warrant the cost of a legal case because they are such niche products. However, precisely because they are niche products (based around active internet communities, no less) you can reach critical mass of public awareness of a copyright infringement very easily.
The copyright boilerplate mod authors put on their works isn't because they're realistically going to go sue someone, it's so they can easily show that, should someone copy their work, the public shaming will ultimately tarnish the thief's name and drive move views to the original work. Of course, "if you copy me, I'll unleash the proverbial hounds" sounds a lot less professional than "this work is copyrighted." Mods can be pretty personal projects (I think this is a big reason Eloraam doesn't get help for RP), so some authors might enforce their copyright legally on principle alone if pushed to it, but I doubt many have the time or money to put into something like that. At least, I have yet to see it.