I'm loving the jsf 2.0 composite component setup. One other thing I love is prependId="false" on forms. Is there an equivalent that can be defined in cc:interface or cc:implementation that will prevent jsf from creating a j_id to prepend to the ids defined within the composite component?
That's not possible. Just give the component a fixed id
instead letting JSF autogenerate one. The same applies on forms by the way. This way you can still select them using CSS selectors.
Or better, just give them a styleClass
so that you don't need to select by ID, for the case that this aversion was actually caused by inability to select components/elements by client ID (I don't see other feasible reasons).