In a former life, I dealt with home gun safes routinely. Rules of thumb:

- Nobody ever bought a safe that was too large.

- Judge quality of safes of the same size by weight.

- Electronic locks are convenient and have cool features, i.e. temporary access codes, hour of access limitations, etc. However, they are nowhere near as reliable as mechanical locks. They will eventually fail, possibly requiring an expensive visit from a locksmith. If you get an e-lock - you might consider keeping any primary defense weapons elsewhere.

- If you are planning on storing indoors - make sure your floor will support it. Larger safes often require additional support.

- Consider placing the safe on a poured concrete pedestal of 6-8" if the situation allows it, i.e. garage or slab floor. This not only makes access to the items on the floor of the safe easier, but it helps reduce the risk from minor flooding.

- Fireproofing is nothing other than sheetrock. If you want a longer rating, simply add more to the safe walls/floors.

- Always, always use humidity control. Two rods (for redundancy) and a large box of desiccant cost less than some boxes of ammo. If you've got items that are worth enough to protect with a safe, it's simply retarded to ignore this extremely minor expense.

- If placing a safe on concrete, either directly or via the pedestal suggestion above - use a vapor barrier. The bottom of the safe will eventually rust out if you don't.

- If bolting a safe down, don't waste your time doing so at the edges. A long prybar combined with a long sawzall blade, will cut through such bolts like butter. If you want to bolt a safe down (typically a good idea), do so in the middle of the safe.

- For larger safes - hire a professional to move/install if not included with the purchase price. The damage they can do to you and your home isn't worth the risk of saving a few $$.