Re having other admins:
I thought this was a bad idea to have more than say 2, but I added 4 more over time, all of which have limited access to the admin CP and I know them personally.
Generally due to the fact that my online access was limited, I added more and that one of the other admins has previous experience too.
I am the only one with full backend access to ftp and the database, so I am safe

Plus its nice to know in the config you cannot be deleted.