Doesn't it work like that already? I was chasing a couple of accounts not too long ago that would delete old posts and then republish in the POB frontend under new names. It took me a long time to recover my DV power that week.
Your query on malicious DV'ing would work well, I think. If someone posts daily and gets rewards zeroed daily (assuming it isn't justified) it would prevent some continuous DVs from occurring. Though I don't know it would be effective against DV trails.