Got H1B stamped but have not travelled to USA

I got my H1B visa ( employer A in USA) stamped on Mar 2016 in India.Visa is valid til Mar 2018.After stamping i have not travelled to USA ,becuase my Employer A doesnt have Job yet for me.
In this condition are these below possible

Can i apply jobs from India to company in USA and join them with H1B transfer,which is without paystubs from my employer A.
After job offer can i travel to USA join employer B with H1B transfer…is H1B transfer possible after joining employer B ?

Pls suggest me best option for the same