既然这是一个从无到有（不是跳槽）的过程, play safe.

"1. My agent said they are going to offer 98K (he is pretty sure that he can get 95K-100K for me), and also told me he think their upper bound would be 105K. I already asked agent to convey my expectation of 105K. Before that I already told agent that my expectation is around 100K when the agent asked me how do I think if they offer me 80K."
-- Top goal 105k;
-- Medium goal: 100k;
-- Aiming top goal, be happy if get mediam goal;


"2. Based on what I feel from agent and HR after interview, they seems very willing to hire me."
-- nice, you will not know untill you get an offer

"3. I asked HR about relocation package and they say they will check whether or not their guidelines/policies are applicable to me. So far no news on that. But my agent say most likely they cannot offer the relocation package."
-- You may still negotiate with them, see what will turns out.

"4. I don't have any job right now - full time house hu*****and. Also never worked in U.S. before. This is the first company which most likely will give me an offer after 2 months job hunting. They have already finished reference checking and started background checking. And I don't think I will have another offer in near future."
-- 既然这是一个从无到有（不是跳槽）的过程，get whatever you can get to play safe. There is not much power you can negotiate.
-- Don't be too greedy, get a good offer and first USA job first.

Thanks!