Code on a site where the owner was banned does generate ads, if the pub ID is changed. I've seen this on a couple of sites I know about. I don't think you need to request that the domain be manually unblocked. It's to do with publisher IDs and not domains, as far as I know.
http://www.webmasterworld.com/forum89/9414.htm In that thread Adsenseadvisor says that they do allow sometimes to show the ads on a banned domain after it changes owner, so I guess you would always have to email adsense support to be sure you aren't buying any problems.
As far as getting banned without being warned, I would confidently guess that in those cases the violations were egregious and extreme. Like we can tell the kid stealing a piece of gum from the corner store that he needs to stop doing that, but that same strategy is not nearly as effective on an bank robber after the fact. Sam you seem like a schemer to me.. You seem to be working angles and not any kind of sound principles... Perhaps you need to re-evaulate what you are trying to accomplish and how you are trying to accomplish it.
Schemer? What the heck? Geez. I know I can't use AdSense anymore, I thought I already said I was just going to wait for Yahoo!