1) Yes, three letters. One is from Japan, one is from the university I am working, another one is from UCLA. My boss wrote one for me, but there is one word which is no good, and the lawyer excluded it. Both letters from USA were provided by Chinese associate professers.
2) Yes. But when EB1 became current, the lawyer sent a notification to USCIS.
3) I provided 3 original letters to the lawyer, I really don't know how they dealt with them. Sorry.
4) Myself. The university is not involved.