As for the RFE, if it asks you to provide employement verification, then you better find a job in the same area ASAP and ask your new employer issue you a employment letter. and you also need to attach a letter explains that you are still working in the same field.
if your employer revoke your 140, you should still be able to get GC, but it may get delayed.
Usually if it is a big company, no one would care to revoke your 140.since it will do noone any good.