Can Proxmox handle constant unclean shutdowns?

I know what I'm doing is wrong, it'd be so much better to (something that will cost 10x as much and still be semi janky), etc.

I plan on getting a mini pc (probably an N97 or N150 cpu), connect it in a minivan, have Proxmox as the main OS and not quite sure of the rest. Definitely something to run an emby server, maybe a couple OS's that can share the gpu (for decoding, I know they won't be able to actually display via the hdmi port so I'd have to use a usb hub with hdmi as a hack). I should be able to get everything setup properly, do a backup, then toss it in the van. If any of the guest OS's get corrupted, just restore from backup (or just have it boot from the backup each time, not saving any changes, can't remember what that's called but I know it's possible).

Question #1, should proxmox itself be able to handle the constant abrupt shutdowns?

Question #2, is there such a thing as an inexpensive 12v ups with a usb monitoring port? Bonus if it just shuts off power completely after X minutes, that way when I turn the van back on and power is restored the mini pc can auto power on.