Hmm, let's see ...
At the very least: sid, uid, tid, date, title, introtext, owner_id
Well, technically uid/owner_id aren't necessary but then all your stories would be owned by "Anonymous".
Converters from other systems are always a problem. People use them once and then don't need them again, so they don't get updated - or even written in the first place. I would hope that changes now that we have out neat "internal API", at least for stories and static pages ...
bye, Dirk