Backup and restore SSH host key(s)
It would be nice to backup the SSH host keys (public and private) from /etc/ssh and restore them if they are in the configuration. Could be optional, but seems like something we'd want to do by default.
Generally speaking, the host keys should follow the config, as if it changes (reinstall, etc) then clients would fail to recognize the host as the same after it's restored, which seems counter-intuitive.
Alternately, we could have a GUI for this (perhaps on system_advanced_admin.php or split the SSH options off to their own page) to manage the keys, which would include them in the config and also give the user an opportunity to easily regenerate them if they want. That may be overkill, however, as it's rarely a necessary step.