1: Why are Prison Escape servers so popular?
You don't have to think, and because there's usually enough administration on the server to get it past the six-player popularity threshold. Sure, the gameplay gets stale, but that doesn't matter when you have an endless supply of new players, and a big name is supporting the server.
2: Will there ever be a sequel to Blockland?
If there will be, it will be fan-made.
3: What will happen in 2017 (Blockland's Tenth Anniversary).
Mocheeze is resurrected from his grave so he can call all of us horrible people. Also, maybe the block party will come back up. The game hasn't been the same for me since it lost popularity and was taken down.
4: Is it possible to create an AT-AT in Blockland with bot legs on a vehicle body?
Depends on how you go about it. Bots supporting a vehicle won't work because the former are idiots and the latter phases in and out of reality, but a full vehicle or full bot would.