Yes you can. Races and factions don't limit it.
That I don't know. But I would assume you can marry. Just a guess though.Also since i still have the Pledge XP boost thingy from Imperial, can I use it with him on those characters or is that something thats faction restricted?
Nope. At least I can't think of anything. I'm not an all-knowing ESO wiki, though - but I know the basics.Is there anything we can't do together other than PvP?