The charge for disassembling a longarm and moving it and reassembling was $350 (last I heard). No, it is not easy. I've set up many longarms. We partially assemble them at the store, then move the partially assembled pieces to the home to finish the assembly.
I can tell when my longarm isn't level when the carriage moves by itself. But it isn't that big of a deal because it's not computerized. I do have the tool to level it with, but it does take two people -- one to check the level as the other turns the adjustment under the foot.
Getting casters is a good idea. Just move it back to the same spot, and it should still be level. You could even mark the floor so you know where to move it back to.