Agreed - a sort of warning really should be there. I completely agre with your analysis of the limited directions of HBP-compliant fanfic - and perhaps this issue is going to become even greater once the last book is out (ok, for those who might still want to write HP fic after that).

Sirius... yes, I also prefer a however skimpy 'how he came back to life' explanation (they're not that hard to do) to totally ignoring his death :).