You can add banned words to your censor list, but as far as limiting links to only certain sites, it may be possible by editing the conversion code in ubb_lib but that would require a modification and since it would be specific to your site would probably require someone to write it specifically for your site.
You'd need to contact those who still code in perl - LK or Charles Capps, possibly Ian Spence. Or maybe even Burak. None of them (except Ian) currently post here at ubbcentral, you may be able to pm them at ubbdev for a paying mod tho.
