Hi jjct1,
I have several Joomla sites running on server 16. Mod_Security does halt some of the actions initially but when that happens you turn in a support ticket and tech support will set the exception for you.
Joomla, like all the php driven CMSs has had it's share of security problems this last year, but the developer group is very active and the forum at Joomla.org has a
great security section. Joomla has made the transition to running with globals_off and using php 4 or 5.