UNIX systems are generally the best system to run perl scripts IMHO.
On your second question, isn't that the case with any website stuff, get the best performing server? I've seen UBB's run well on free web hosts, so most paid hosts will run them just fine.
On the frame issue, somone else will have to answer that. I just know its not a built-in feature and would probably require some heavy script modifications to get it to work that way.
Currently there is no automatic backup component of UBB. Right now you either rely on your web host making periodic backups or you backup your site yourself via FTP. I would say to restore a backup would generally require about an hour max.
------------------
Doug
Moderator: Cool UBB Examples
I am altering the deal. Pray I don't alter it any further.