This type of question was probably asked a 100 times in 100 different ways by others, but please take time to answer this or direct me to a thread that already has the answers....Thank you 
If my current employer has filed my labor (PERM) and I-140 under EB3 and after the I-140 approval I decide to change employers then please advise if the following is possible.
1. Can I retain the same priority date but do a new labor and 140 with my new employer?
2. Can I go for EB2 with the new employer and still retain the date?
3. If my current employer does not provide me the copies of labor and 140, can I still approach USCIS and get those copies through another attorney?
4. If my current employer revokes the 140 then can I still port that PD date?
5. Some sites say that "only I-140s revoked for fraud or misrepresentation" affect the porting of PD dates while others say that if the current employer decides to revoke the 140 then the LC and hence PD is automatically invalid
6. Some site claim that from the time of submitting a revoke application the USCIS take about 2 months to process it. If the new company I join is ready to process my labor(PERM) in that window then can I capture the PD from my earlier LC?
The reason for all these permutations is the mixed reviews I see in different sites. Some say that PD porting perfectly works, others claim that they had to fight for it and others say that they were plainly refused. So please throw in your valuable inputs
If my current employer has filed my labor (PERM) and I-140 under EB3 and after the I-140 approval I decide to change employers then please advise if the following is possible.
1. Can I retain the same priority date but do a new labor and 140 with my new employer?
2. Can I go for EB2 with the new employer and still retain the date?
3. If my current employer does not provide me the copies of labor and 140, can I still approach USCIS and get those copies through another attorney?
4. If my current employer revokes the 140 then can I still port that PD date?
5. Some sites say that "only I-140s revoked for fraud or misrepresentation" affect the porting of PD dates while others say that if the current employer decides to revoke the 140 then the LC and hence PD is automatically invalid
6. Some site claim that from the time of submitting a revoke application the USCIS take about 2 months to process it. If the new company I join is ready to process my labor(PERM) in that window then can I capture the PD from my earlier LC?
The reason for all these permutations is the mixed reviews I see in different sites. Some say that PD porting perfectly works, others claim that they had to fight for it and others say that they were plainly refused. So please throw in your valuable inputs