How easy is h1b transfer while in india or after studying in USA

USA H1B Visa
1

  1. I have h1b approved (not stamped) but not traveled yet.The sponsorer has just shared a mail that my petition was approved without any details like reference number,I-797 etc. Without such documents how easy it is to transfer h1b to another employer in india.

  2. what will happen if i resign the company and proceed for higher education in US. Can i transfer that visa to another company in US or if i join the same company after completing higher education will the h1b visa be still valid.