Do mods apply to other clans and NPCs?
 

I've been messing around in the "Assets" folders to mod the game, and wanted to try creating a mod that would give my character major gold drops, so I could have more control over the total economy, and another that increased the speed of my leveling. In both cases, it seemed like the other clans benefitted from this as well - they all wound up with tons of gold in the first case, and characters of around the same level as mine in the second.

Do mods affect every character in the game? If so, is there any way to mod it so that these benefits only affect the PC?

Yes, it will affect everyone else also. There aren't really ways to affect just the player.