For the moment, I'm the only admin and I have control of everything (domain + server). There aren't currently any backup plans in place as other things got in the way. There was some discussion of setting up a Bitwarden premium account which would let someone have emergency access to the server passwords, but I'd need someone to volunteer for that now (if anyone's interested helping the admin side of things, lmk).
And thinking about it, I should probably remove tom from the admin list just so people don't contact them with random queries.