Job change after subnission of 485 based on NIW-140 kunlun2007-08-17 00:05:43

The situation is: applicant is on OPT and submitted 485 (NIW based 140 approved). Now quited from the first job and is waiting for the offer of another one. There are several questions

1. Is an employment letter required for 485 at all? If it is, what to do if there is a job change after submission of 485?
2. Will the job change and location change (to a different state) result in an interview with the USCIS local office?
Please tell as much as you can and don't be restricted to the two questions.

Thanks

回复：Job change after subnission of 485 based on NIW-140