I created a dhampir tetori with Fangs in PFS, if i have the feats Blood Drinker,improve grapple, greater grapple, and rapid grappler, may i grapple a foe with standard act, maintain the hold with move act by greater grapple to bite and use Blood Drinker, then maintain the hold with swift act by rapid grappler to bite and use Blood Drinker again ?
The whole "standard action, move action, swift action" thing, and the feats you name, were first edition Pathfinder. None of it made it into second edition Pathfinder. I'd figure you were in a group that had decided to stay 1e, in which case your query belongs here---but you said PFS, which I didn't think had 1e tables now. PFS-specific questions would belong here. (This forum is for non-PFS-specific discussion of second edition rules.)
All that said, I believe the answer is Yes, but my 1e memories are hardly fresh.