请教8老师

1. can downgrade of EB2 to EB3 I140 use premium processing?

2. concurrent filing of I-140 and 485 是根据表A 还是表B上的日期?

3. is it better to do the downgrade from EB2 to EB3 before hand or wait till the Priority Date is current?

4. if Priority Date is current， can concurrent filing of I-140(downgrade from EB2 to EB3) and 485 use premium processing together?

5. Since I-140 is for main applicant, but 485 can be for dependant, can concurrent filing with premium processing for the entire family?

6. how can the expedite processing be done for 485? any fees for each family member?

7. According to USCIS website, regular processing time of I140 is 15-22 months. If filing I140 without premium processing, Priority Date becomes currently when waiting for I-140 approval, can I-485 and combo card be filed?  or have to change I-140 to Premium Processing first and until I797 notice of approval is received then file I-485?

Thank you!