1) Can i keep my Priority Date and apply for the Greencard later (after graduating from school) with it? Would that be possible even if the job is not similar to the one for which I got the labor approval this time around?
2) Would it be possible to keep the 485 active when I am in school? If it helps, my Ph.D is in the same field as my Masters (also from the US).
3) If I receive an RFE on my 485 about employment etc and I can't respond, would that have any effect on the validity of my F-1?
4) After I got the F-1, I re-entered the country back on my H-1 since I wanted to continue to work for a bit. My H-1 expires in a few weeks.
5) Should i withdraw the 485? If not, will I get into trouble while going out and coming back in?
6) I'd need to inform USCIS of my address change. If I'm keeping the 485 active, I'd have to specifically mention the address change for those applications as well. Should I just go ahead and do that?
1) You should be able to keep your PD because your I-140 is approved. The jobs do not have to be similar, but you do have to start your GC all over again.
2) Only if the employer (or some other employer with a similar job - AC21) holds the job open for you and you have the intention of joining them upon approval of GC or earlier. But do keep in mind the next answer.
3) I see no effect. But do remember, USCIS has indicated that F-1 and AOS cannot both co-exist. We do not have much elaboration on this statement.
4) You can stay as an adjustee.
5) This is unchartered territory.
6) All nonimmigrants have to file AR-11. You can do it online.