59" high, 51" wide and 51" deep. For larger width or depth you can install two cages back to back to fully enclose.
Yes that’s the only difference
Combination lock on the side. The cage slides over two round metal pieces that are anchored into concrete. So you put a lock on it just like you would a trailer or a shed. Undo the lock and pick the hole thing up.
The instruction are easy to follow and I had mine done in 30 minutes.
It will depend on the size of your AC pad. I had to add 2 inches around my existing pad in order to mount the AC cage.