True enough, don't use paypal much anymore so I'd forgotten about that particular feature, but again the "verification" really doesn't have to be 100% perfect, just enough to discourage the scriptkiddies and scammers a bit to cut down on the workload for the quality reviewers.
The real first line of is the reviewers themselves, the second line is the ability for people on the site to report people who are abusing the system to the reviewers for immediate action.
With that system in place it really doesn't do them much good to change ID's every 10 minutes, they still can't get any revenue unless the upload an acceptable quality product.
Since the scammers can't maintain that standard, they won't stay in the second tier long enough to be eligible for a payout, assuming you still keep the payments on a once a month.
If you lose your status as a revenue sharer, you forfiet all your claims on any portion of that revenue. The scammers can't upload tons of crap and generate tons of clicks for it anymore, doing so is obvious to the rest of the site members and they'll get reported in a heartbeat.