I agree, but it would double the cost of the house to bullet proof a house of 2000 sq. ft. $300,000.00 to $400,000.00.
Not if ya built it from Strawbale + Stucco walls.. Both Quite fire and bullet - resistant - (very-little material / construction is Truly bullet"proof" - just ask .50BMG or 20 or 30mm Vulcan rounds.. and Certainly far more cost/benefit-ratio friendly to the wallet-side, than even Brick.
..And, there's a Lot that can be done to 'harden a structure' against gunfire / doors against kick-ins, that's (relatively) cheap and quite DIYable (ie: anti-smash film / grates for ground-level windows; Doors that Only open Outwards, and are Solid-core / or steel-plated, even, whatever.. Plenty of Options for Far-less than trying to do such with 'kevlar-panels' (or whatever it was you were thinking of to get to the Est. of $3-400K, etc)
..Heck, even Sourdough's recent idea of autobody resin-impregnated fiberglass 'welding blankets', as cheap, DIY bullet-resistant large-panels.. Work Quite well (for small-arms fire) and certainly cheaper than similar-sized panels of kevlar.. Or, those + UHMWP-panels, etc.. Again, lots of workable ideas.
re: the 'Portable firesafe'.. @Sourdough, Chief - I, for one, would take the testimonial .02 of a Structural / Wildland Firefighter at face value (which is High
..Personally, if you're looking for "max portability", I'd take that Pelican ya have (and heck, you could even get a Bigger one (ie: Pelican 1660 is a Good-size 'trunk', and can be had, Used, quite inexpensively (compared to new) - I've found them for as little as $150. functionally like New (who Cares about 'cosmetics', etc) ...and Bury it below the frost line - Bada-bing - "Fireproofed".
Internally, put several dessicant / dry-boxes inside (and, perhaps even some O2 absorbers) just to help keep mold / dank from forming (Pics / Critical Docs I'd seal in mylar or at Least 2x ziploc-baggies, etc) Should be fine.
I have other ideas (relative to 'water / freeze mitigation') but that's all irrelevant, Unless / until you wanted to consider this 'pit' as an idea, so for now, I'ma shuddup.
.02
jd