Howdy! I know that you can disable the root account (though I didn't know the command for it, thanks!). I was just wondering why it was there, since Ubuntu doesn't come with it by default, and then you have to instruct users to change the passwords of two accounts instead of one, especially since the user account has sudo privs! It seems like it might be a better choice to leave people with only one account to deal with; however, I have no knowledge of the process you're using to create the liveDVD, so if it's based off of an installation you have to use, then I understand.
Regarding forums, I briefly talked this over with Michael Gage in another thread (look at sidenote 1 in my 2nd post). As I indicated there, I haven't administrated any forums, only used them. Based on what I was seeing here and my difficulties in determining how to use it (mostly as far as registration), I was guessing it was a hack on something. I didn't really understand what Moodle was at all (I actually need to look more into that now).
How often are mathematics actually used in these forums? I've only had a brief look, but it seems like [code] tags are the only thing beyond a basic forum that are needed.
It appears that there is a plugin for phpBB to support jsMath, btw.
While MediaWiki certainly has math support, it's not really meant to be used as a forum, and doing so tends to create problems. If you've been active in discussions and such on Wikipedia, you'll know what I mean. There's really no way to subscribe to new messages in a topic, or to really *have* a topic in the first place (you have to create subpages and have them included in). People always forget to sign messages, leading to a SineBot that patrolls RC and adds signatures! On the whole, I'd rather use this, as it is at least a forum, rather than a wiki.