1.Current market is still hot, so you will have bidding war. Seller won't give you discount even you present by yourself. But some buyer agents will give you around 0.25-1% rebate.
2.You bid with other people, not only chinese.
3.That's true, it maybe more serious. It depends on you, if you don't trust this house, just go away.
4.Yes, generally, title insurance is good enough.