I am going to set up a second node in a second location for redundancy purposes. Can I set it up using the same backup keys as the first node or should I set it up completely new? Thanks in advance for any input.
No. If you use the same LN channels backup it will close all of them and you can even be penalized.
Just use another nodeID. You can even use them connected each other with private LN channels, for doing other stuff.
In case that one node is crashed, you can copy the blockchain data from the liove one.
If you have a good PC with Linux/Debian, you can use a RAID configuration (0 or 5) with multiple disks so you will not worry anymore about crashed disks.
Can I reset the seed words in an umbrel node without starting from scratch? Thanks!
Do this only if you do not have any funds on your LND wallet! If you have funds, then save your seed + backup file so you are able to restore it later if needed.
You are going to loose your seed, settings, data and applications!
Enter using SSH and run the following:
sudo systemctl stop umbrel-startup && sudo rm -rf ~/umbrel/lnd/!(lnd.conf) && sudo rm ~/umbrel/db/user.json && sudo rm ~/umbrel/db/umbrel-seed/seed && sudo systemctl start umbrel-startup