Backtagging: Of course.
Threadhopping: As long as it's not a private communication, I'm all for it.
Romance/Relationship: William takes a little while to warm up. He comes from a very homophobic place and the threat of reaction is something that generally stops him in his tracks. He wouldn't therefore instigate anything himself. That doesn't mean he's not open to romance. He's certainly craves it, and once sure of his safety he would be far more willing and eager. As for friendships he is down for anyone and anything.
Physical Violence: He won't be the person to start the fight, but he definitely will end. He's well trained with a sword and hand to hand sparring. He would also be very protective of people who can't take care of themselves and may step in if he thinks someone needs it.
Mental/Magic: William has no mental protection against magic or things like telepathy so he'll be easy to control. Hit me up if you want to plot something.

athosing