On the subject of griefers, my set of domes, the observation tower, and Heward's Handy Hovel got hit at some point. I'm not on with any real degree of frequency anymore, so I didn't make any repairs, except to remove the TNT penis built outside and properly rehinge the iron door, operated by the keypad lock. (That door is hinged on the right, when viewed from the keypad, by the way. That's deliberate, and necessary for proper interaction with the lock's circuitry, so if you are ripping the door off, in the name of exploration, make sure to put it back on properly.)
Incidentally, if anyone is interested in repairing/maintaining the domes, observation tower, and Heward's Handy Hovel, in the future, I'll turn over the code to that lock and relinquish any materials in my storage area for your use. (There's still nine diamond blocks in one of those chests, so it's a worthwhile offer, to anyone still digging for their materials in Survival mode.) Just shoot me a PM to let me know you're interested.