Visa Stampng is imandatory if we change the comp on H1B valid stamp if we visit India

[krusaccount]

Hi Friends,

Currently i am on H1B Visa with Company A, validity Until Jan 31st 2016. my family also have visas with same validity India.
I have plans to changes the Company B by this Dec 2014 and Planning to visit India in Feb 2015.
1. If i visit India after changing company to B, still is it mandatory to go for stamping with Company B papers ?
2. Can i come back with Valid, Approved petition of Company B as i am having Company A Stamped Visa.
3. If there is chance for above point 2 , will there be any issue while GC process



Please suggest me thanks a lot in advance for helping me.

thanks
kK