I have priority date of Jan-2011 and I-140 is approved in Mar-2011 in EB2 category(Country-India).
I have good offer from another company and so I have questions for GC in below scenarios.

1. Can I use priority date (jan-2011) if I change the job and file GC with new employer OR
the rule is I can only use priority date after six(6) months of I-140 approval date?
2. I heard that priority date may become current for India EB2 this year or next year, In that case if my new employer will not file my GC soon and will file GC after 6 months or a year later. Can I use my old priority date (jan-2011) if later USCIS do any changes in priority date from current to any other date ?
3. what do you suggest - is it good to change job at this time or better to wait till get EAD ?
Thanks,