yeah I would go with texture sets, use Fo4Edit and look at what other mods do regarding settlers and new outfits and use that info to do stuff in CK or Fo4Edit. with new factions, you can try, but it may be quite a big undertaking. Get a piece of paper- here is a Wikipedia page on what this stuff is https://en.wikipedia.org/wiki/Paper , I've never heard of it.... - and right down a list of what exactly you want to do, since you'll need to plan it out first . look at all the armour meshes in the game and see if you can use them