FTP/SSH access would be useful for hiring out for upgrades and modifications (or doing them yourself).
Access to PHPMyAdmin and the MySQL DB username/password would also be useful for editing the MySQL database (the user/password can be taken out of the ubb config file however).
Access to the Control Panel for hosting would also be useful as it'll allow you to access server logs (as would SSH access noted above).
Some webhosts do not allow access via SSH, which can be semi understandable in a shared hosting environment; but definite access to FTP and PHPMyAdmin (if installed on the server) would be bare minimums for maintaining a site.
