Either trueNAS or unraid work as a vm in Proxmox, but there’s some caveats. You have to pass the whole hba/lsi pcie device to the vm so you can’t split the backplane of the server.

Those don’t seal well, so probably not

Aircraft maintenance has been doing the negative pressure unlock tests on cockpit doors for decades, its honestly surprising what isn’t common knowledge. Like others have said, rapid decompression of only a portion of the aircraft is very bad, and will result in massive structural failure as individual compartments aren’t pressure rated and will blow apart. The doors I’ve had experience with had large panels that would pop out when in a negative pressure event.