They wouldn't know if they were a QA, but they might know if they were a snap bid.

I've known a bunch of fairly recent new members (from 2000 on) who've attended competitive universities who admitted that they got their 2nd or 3rd choices. I hope they never told their sororities, though. All ended up being great members!

It does happen. Thankfully, these members often have a good attitude, and their sisters never know the difference.

I don't know how one could know if she is a quota addition.

I understand that quota is based on how many girls are LEFT on the last day

and if Panhel tells the houses how many PNMs to cut each round, then wonderful women get left out

Not unless they only focus on the top chapters. RFM is there to force the sororities AND the PNMs to "get real." Too many sororities were asking back women they had no intention of bidding just to make themselves look super popular, and too many PNMs were focusing only on 2 or three top chapters. RFM prevents that. If the women don't have open minds and don't want to look at the chapters that have asked them back, that's their loss.