I have been offered a state job, whose requirements are a Bachelor's degree with a 1 year experience. However, I have a US-based Master's degree. From what I understood from the text above, my green card can not be filed under EB2. I have talked to my employer about it and they have indicated that they are willing to help me in any way they can. If I were to request them to hire me in another position and advertise the new job requirements (Master's) after I'm hired, will I be eligible under the EB2 category?
You are correct. You will not qualify for an EB2 unless the job also legitimately requires a post graduate degree or Bach. with five years of experience at a minimum.