Thank you very much for the analyses.
1. 租客临走最后一个月房租未交，数量相当于押金。结果是，租客走后，你手里没有押金。但租客对房屋有损坏，你联系要对方赔偿，被拒。Here the deposit was 2-month rent. So they did not pay the last two-month rent. But they paid $100 late fees to avoid being vacated and had a lawyer dealing with me saying they were setting up another security deposit.
2. 现在租客包裹到了你手里，你想扣押，迫使对方赔偿你的房屋损失。I wish I could do that, but will not really do it. Just want to give them some trouble. Tomorrow morning I will write to them asking them to re-arrange pick-up, etc.
I also thought about damages on their goods. As long as they were not caused by us, we are not responsible for the damages.
3. 你认为法庭not landlord-friendly，不打算用法律解决问题。
The problem is the previous tenant are not easy to deal with. Right now, they have the legal advantage. I doubt they will make any negotiation at all.
