You basically have two choices, one deal with it, or two, remove the guns or safe. We recently sold our house. Went through a couple of open houses and about 40 showings. Never had any kind of problem. I had built a cabinet around my safe when we moved in, just to keep it more or less out of sight. When the house went up for sale, I put a little "tell tale" on top of the cabinet door so I would know it had been opened. I also always set the dial to a specific number. After every showing, the door had been opened, but the dial had never been touched. Nobody ever made a comment about it.
The realtors tell you in the beginning to empty the clutter, and getting as much of your gun related stuff out to doesnt hurt. Having a 125 pound Rottie running around the house, requiring that they give you notice and a specific time they are coming, so you can get the dog out(and the reason why) and not leaving a lock box on the door until you leave, keeps you in a little more control and some of the worry down.
As sort of a side note here, when you move, look into getting a piano dolly. They make moving the safe a whole lot easier, and safer. Works great if you just have to move it around for rugs and such too. I was able to move mine around with the guns still in it when they did our floors.
Good luck selling your house and with the move. The market here took a major dump and screeched to a halt. We got out of ours just in time. Carrying two mortgages really sucks!