Don't stress XHTML/HTML compliance. The fact of the matter is there won't be many blind/elderly/screen reading people looking for a clan, so you're all set. As a designer I stress compliance on my own professional website (http://www.msbconsulting.net) but for entertainment sites and the like -- not so important.
Oh and also -- XHTML sucks lol. I've been using XHTML/CSS for about a year and I hate it. I want so badly to go back to tables, and at some point probably will but for now I'm sticking with the 'fad'. My biggest beef is the hacks you have to do in CSS in order to get certain browsers to ignore certain definitions, etc. That to me is like breaking something to make it render properly. :shakes head:
IMHO don't fuss over XHTML if you don't know it. Just make sure you're using valid HTML/CSS and you'll be all set.