Storing firearms:
(1) Mentioned already is a false closet back. No need to screw it in, try a friction fit or magnetic latch. Deception is key: I know a person with a valuable antique firearms collection that lived in a remote area and employment that kept him away for a few days at a time. A truck and a few persons to carry out a gun safe would be an easy job. He installed a furnace heater shell next to the identical functioning unit, ran wires, ductwork, plumbing, filter, kept his collection inside.
(2) Basements and upper floors with only a single way in/out are a deterrent. Most burglars want another way out in addition to the way they came in, and first thing they do is unlock and open another doorway.
(3) Leave a few $20 bills on a table. Most kids will grab and run without going through the rest of your residence. Your $1,000 laptop is worth about $20 on the street.
(4) Leave in the open a firearm you are willing to loose (like a hardware store single barrel shotgun). I've seen an India made Lee Enfield Mk1 with bayonet attached as a sacrifice ... some kid who doesn't know how to dismount the 24" bayonet stuffing it in a car trunk would be a sight to behold!
(5) All the burglar alarms, TV cameras, alarm systems will be neutralized by a really skilled burglar that knows you have a valuable firearms collection. Safeguard youself with photos and insurance.