Holy crap, Al! I thought you lived near my neck of the woods, but that's some serious crime against you. Your line of work sounds like a lot of fun though. People don't even lock their doors here, and I'll have to remember what it was like living west of the Cascades. I've been living in a smallish town with very low crime, a stellar education system, and friendly people for 16 years. It will be a major adjustment. Even though I have the construction skills, I doubt my sister would allow me to build a bomb shelter in her home. You are absolutely correct about water protection. I have repaired many thousands of dollars of water damage. You'd be amazed at how much damage an overflowing toilet on the third floor can do.
From the responses so far, it seems like my best bet is to get something fairly inexpensive and rely more on being smart about it. When I build my next house, I'll consider constructing the 2-foot-thick reinforced concrete vault. For now, I should probably stick with something simple. As mentioned before, the guns are replaceable. But the guitar and few other things are not.
Ohh, I'm not in a high crime area, just old

had some stuff happen.....Portland isn't even "high crime" compared to eastern cities, ever'body's HIGH, but most of them are smiling vacantly not breaking into stuff. It's the jobsites and outlying areas that have the stuff getting ripped off by folks on hard drugs and opioids. We call 'em tweakers and they're in every state/county/town in This 'Lustrous Union..... they run around jobsites all night looking for tools, wire, lumber, metal parts they can sell for scrap....
My first vehicle was stolen from my home back in Sandstone Minn'DesoDa because my apartment was just 3 blocks from the bar.
The others were taken from jobsites in various towns (Washougal WA is THE WORST for tweaker theft!) where we leave them for extended periods of time. And I've had several taken into custody by the over-zealous street patrol nazi lady they hired when they passed a law saying "any vehicle parked on a city street for over 24hrs must be moved or is subject to impoundment"..... an awesome example of a well-meant law gone awry.
When I say "I take security seriously" that means I seriously weigh options and consider implications..... and in many cases my actions run completely counter to accepted practice. Like not locking the doors on my jobsite rigs. We lock away the keys, in lockboxes, but locking the cabs on equipment just means they heave a rock thru the window to rifle thru the glovebox. Leave it unlocked and they'll still mess up the cab but most times nothing's broken.
Same with "home security"..... a doghouse, a large pair of boots or a target set up in the yard are often better deterrents than locks or a "security system." I giggle when I see 9 deadbolts installed acros't the front of a home (with huge windows) and the sides and backs of the home all privacy-fenced and dark (with huge windows and glass doors)
naahhhhh, regardless what you hear, you'll still love Portland, and will be perfectly safe. Unlike Pittsburgh or Chi'Cago, when that guy sidles up to you he's just trying to sell you something, not hit you. Portland is WEIRD (I mean, 'Portlandia' IS a documentary...) but it's not high crime. And for out here it ain't even that weird.... if a guy runs around nekkid in Portland he'll still get beat up, unlike CA where you have to put down towels on the seats in Mickey Dee's...