Honest, it's easy. I am administrator of a small (40 - 50) FB installation, and the only skill I needed was to be able to read the online help.
Installation (at least of the Windows version) is dead easy, and deploying plugins is simply a matter of downloading them, and then navigating to the Plugin page, and clicking on the Upload Plugin link.
It probably helps to know a little about whichever platform you intend to deploy on (IIS/Apache/etc) and the underlying database, but I've been able to get away with the bare minimum - I still know very little about either.
If you are planning to migrate to FogBugz, it's a different story, but essentially any scripting language which can read the old data and write XML to the FB server will do the trick.