但是顯然他們認為他們不能promise
-Not need they show the promise to USCIS, but USCIS may ask them to provide the financial statement, bank accounts, etc. to show their ability to pay. Not hurt the employer anything when you file your I-485. After your I-485 pending is > 180 days, you can change a job in the same/similar area, then your new employer does not need to prove the ability to pay (not need to pay you salary at the prevail level after you get the green card). So, your current employer does not need to pay your salary at the prevail wage at any time. So, just discuss this to your employer and the lawyer.
因為prevailing wage比現在的工資高了２５％
-If you ahve no choice, may just file your I-485 to see what happen. Even if your I-485 is denied, your I-140 is still valid and you can re-file I-485 in the future.
My suggestion:
if your employer/lawyer does not agree to give you th employment letter and you have the copy of I-140 approval notice or receipt, you can just file the I-485 yourself and provide the H1 approval notice with I-94 and recent 3 to 6 months paycheck stubs with the I-485 filing. Then, tgry to find a job and chnage the employer after your I-485 pending is > = 180 days.
If you don't have the I-140 approval notice or receipt, but you have the receipt#, you may just print out the online case status for the I-485 filing.
