I doubt if buying traffic from AdWords would get your account disabled, because there's nothing in the program policies that says you can't do that. Still, if you were driving a lot of traffic to an "AdSense arbitrage" site with AdWords, and if clicks from the landing pages were converting poorly for advertisers, it's possible that those clicks could be judged "invalid"--but I shouldn't think that would happen unless the landing pages were unable to fail the "sniff test" in a manual review. (Mind you, I'm only guessing, because only Google really knows.)