unpaid item opened 3 days ago. Can close it tonight, can I leave neg feedback ?

[hsvcc64]

Hi all, a few days ago I posted about an unpaying buyer. Since then I contacted her, she didn't respond so I opened up a case. She has until tonight to pay or contact me before I can close the case (the 4 days after opening a case). I just have a few quick questions:

1. I want to leave negative feedback for her to warn other sellers/buyers. Can I do this now? Or after the case is closed?
2. Can she also leave negative feedback for me still (although I haven't done anything wrong but expect payment for an auction she won)
Sorry I'm still new on the side of having a non paying buyer! 🙂
Thank you ! 🙂

[tstore]

1- sellers are unable to leave negative feedback since 2008 even if buyer pays
2- once closed, buyer will be unable to leave any feedback

[phorum_junkie*]

How would you leaving a neg warn other sellers? Even if they took the time to check the feedback of every single bidder on their auctions that still wouldn't stop them getting a last minute snipe or the buyer using BIN.