I don't really know about the questions you asked... dreams are mysterious things. But I've noticed that these first few night's I've had sober, my dreams have been more viscerally vivid overall, and stick with me more the next day - whether they're good or bad.
I'm sure that as you start replacing your old life with new and engaging things in your new life, your dreams will slowly start to reflect that, and I'd imagine you'll dream less often about addiction-related stuff. Fingers crossed for you that that happens as quickly as possible! I know how bad nightmares suck, and how the really twisted ones can cling to you even after you wake up. :-\