H1B transfer after petition cancel/revoked: never traveled to USA with h1b

[richardr]

I got my h1b approved and stamped from company A and I never traveled to US yet.Below are the details
I-797 valid until Nov 2021
H1B stamp valid until Nov 2021

Since my company A do not have oppurtunity I need to move to company B. 
So my queries are:
1. Can i quit my company A first, and then move to a company B( US or india) who can do the h1b transfer?
2. Can company A cancel my h1b(visa/petition) and will that have any impact, Company B may not be able/intrested to transfer h1b since h1b is cancelled or revoked by company A?
3. Do i need to go for stamping for Company B after h1b transfer? Can i not use the existing h1b visa stamping and Company B petition to enter US?

[richardr]

Does anyone knows answer/direction to these queries? 

[gopalakrishnach]

I am not an expert and below are my personal feelings

1. Yes.

2. By law, A must inform USCIS that you no longer work for them and must revoke H1B. Intention of B we cannot say.

3. While you in India, B can apply for transfer and get it approved. You can come to USA with existing visa but you need to carry H1B approval of B.