Hi Bander!
That sounds one COOL campaign!
Welcome aboard - I'm pretty sure that BRP is keeping all the rules you mention, although there are no specific priest or shaman rules in the first release (no divine magic per se). We're all expecting magic systems to be a pretty high priority for upcoming releases following the core book, plus of course your RQ3 / Stormbringer stuff will still work fine with the new rules!
Cheers,
Sarah