I have a few comments about this. Disclaimer: I pirate software on occasion.
1. Don't Do the Check at Startup
I don't actually have anything to say about this. I agree with everything.
2. Be Sneaky
While probably more effective at deceiving crackers (although if Arkham Asylum really was cracked before it was released, it may not be), it is absolutely imperative that everyone knows that the bad gameplay is due to DRM. Otherwise, you'll get pirates complaining about the game to potential customers.
3. Poison the Pirate Well
A good idea, and certainly preferable to non-free DLC. You probably should disclose where the DRM is, though, so no one confuses a bug for DRM or vice-versa.
4. Don't Forget the Customers
This would be better than current implementations, but it still reeks of the artificial restrictions that people hate about DRM. Stardock's approach is vastly superior, with no CD checks at all, ever. Your approach will screw over the folks who don't like carrying around their CD's after the activation servers are taken down, not to mention people who buy such a game second hand, which will have already been activated.
5. Keep it Simple
I pretty much agree with all this, too.
You'll probably also have problems from the corporate side. Given that DRM doesn't prevent much piracy and interferes with legitimate customers, I suspect modern DRM isn't meant to stop or curb piracy at all. It seems more likely that the goal is to shut down the second-hand game market, a goal your scheme does very little to advance.