Hmmm... It's strange, my friend was banned from AdSense 3 months ago and surprisingly, when he applied again (3 days ago), he was accepted! Do you think he'll be banned again because he had a record?
Tell him not too get too excited though. There's always a chance he'll get banned on or just before pay day.
If it will not take him a long time to get to that point, i say go for it. Try it and see what happens.
It's quite cunning really - Google gets paid by the AdWords advertiser but don't have to pay the previously banned publisher so they end up further in profit. No wonder they're the worlds largest search engine!
I doubt it, why do you think adsense is so profitable for them, apart from the fact they take 20% of your earnings.