My opinion on two admins: The problem with two admins is that we would have to trust someone to keep the backup admin account safe and sound who has password access to it- you can't change the password without having access. At that point, why not just trust the person with admin?
The next issue with backup admin is with the standard admin- they could just manually change the backup admin's password/email and take it over.
Finally, I'm just going to say that whoever becomes admin... we probably chose them for a reason. After TFF's history, I don't think admin abandonment will be an issue. Regarding acts of god, that's something that we shouldn't try to plan for imo. If nothing else, once the admin is chosen, we could get them to ask spork to see if he would be willing to pass the board onto a member of the boards choice, should the be admin go AWOL. To prevent another nicknumbers attempt, he will only pass it on to a member chosen by the majority.
tl;dr: I'm of the opinion that in it's current state, having and admin and a backup admin is physically just having two admins in the current implementation (a combination password would fail- someone has to SET that master password and then distribute the keys. Also, if mods go AWOL, we've lost the account.) It also allows a sense that one could just abandon their post, because the other admin could pick it up.
Next, how myBB bans work. A "Banned" member on myBB is just a standard user class, like Registered, with custom permissions, typically set to, by default, be able to view all threads, but not post threads, reply in threads, etc.
Finally: regarding backups. icyboards backs up twice a week, and to use that backup is free and will be done for us in the event of Shit Going Down. If we want the physical SQL backup itself, it will cost 20$. Please keep in mind- even if we get the backup, we have to find a host that can use that kind of a database, which is going to cost many, many monies just for importing the database, let alone the hosting. That's why we're on icyboards- they were willing to do it for free just so TFF could have a new home.
Finally: there are crawler bots available on the web. I cannot vouch for their reliability or speed.