I've performed the same steps on several machines myself :)

What I was thinking was to add these to the observium patch and add a wrapper script around the observium 'addhost.php' script that remote shelled into a server, checked to see if snmpd was already installed. If snmpd was not installed then to run these steps before calling addhost.php.

The other option is to make people ssh into the servers themselves and pull the package from the observium server and run it manually.

Of course, I'd need to add support for non-debian based distributions as well but that should be pretty trivial.