Concurrent filing means that the I-140 and I-485 are filed together

There is no requirement for the beneficiary to be employed by the petitioner during the PERM and I-140 stages but once the I-485 is approved, the...

The NVC sets the visa interview date but an expedited date can be requested depending on the reason

Yes, you can travel to other states outside of your POE

If your case is selected in the H1B lottery and your H1B is approved, the visa stamping would be done in your home country

If you enter into a marriage in good faith with a US citizen, you can apply for a green card

I-140 is eligible for premium processing but not the I-485. Premium processing helps since your I-485 is based on I-140 approval. I suggest you...

If you get approved for a NIW petition and you apply and get approved for AOS, then you will be a green card holder and will no longer be on H1B

The law doesn't require any waiting time to be on H1B. The PERM can be started already if the employer is amenable to this

More facts are needed to explore other options. I suggest you work with an immigration attorney.