angel+sam
I'm not sure. I just knew it was happening, and had to track down the demons that had the souls in order to get them back to their owners. Souls in my world, though -- or at least, human souls -- they float right back to their owners when you release them from wherever they're being held. It's a shame yours is more complicated.
I have a pair of cuffs inscribed with a devil's trap. Failing that, there are ways to carve them onto bullets. The cuffs are better because they also keep him physically bound. But, yes, without being trapped, he could do either of those things, and worse. Crowley's probably teaching him any number of tricks.
Yes, and no. I've cured him once before, but didn't manage to get the Mark off him before he died again. This time I have to do it right.