I had a leave of absence from Employer that ended in June 2010. During the time I was abroad close to family and worked with another employer and entered the US every six months. On february 2011, my I485 was approved and I left my job overseas and entered the US. Currently I dont have a job and I am entering the US every six months. Am I still legal ? or since my approval came after my leave of absense expired meaning that it is no longer valid? How could I maintain my greencard if I need to temporarily live overseas for a while since my mother is living abroad? how about taxes? I would like to keep my greencard ? Please let me know ?
I do have a mailing address and a bank account in the US. It was EB3 category

Thanks

Maher