Exit and Reentry into china for residence permit holder

ill be applying for residence permit through my X1 as im coming for one year course. In between the course can i exit and reenter china any time by my residence permit certificate. I have plan to go out of china for 2 months for my work contract during my course. i am not sure if i can do it ...

1) Will university allow me to go out for such long period ?
2) Do i need to report to P.S.B. about my exit and rentry dates ?
3) Does my country's international airport recognizes china residence permit as X1 to china and allow me to reenter china ?
4) Do i need visa everytime i reenter china during the validity of my residence permit