yup you got it. both numbers have to be equal (or x has to be greater than y) - then you will be able to place buildings everywhere with the mapeditor.
Yea, but it is hilarious... it looks like the laser mine is stuck to player's face. If you're wearing nightvision goggles it looks like a more advanced nightvision goggles.
Maybe the laser mine could be a bit more offset from player's face.