Change of employers before I-140 filing

[pd5009]

Hello,
My employer has started my GC process around a month ago and am looking for a potential change of employment.
My employer is ready to continue my GC process and file I-140 once the I-140 filing stage approaches, right now its in wage determination phase with DOL.

Question: 
1) Can I retain my priority date whenever my I-140 is approved and transfer it to my new employer?
2) Does this have any negative impact on the GC process?
3) My new employer is also willing to start the GC process, can I have two processes running in parallel from different employers? (Not sure if this really helps my GC process)

Thanks.

[jairichi]

1. Yes, you can retain PD.

2. No.

3. Yes.

[pd5009]

Thanks!