Within USA Rejecting offer from Employer B after H1 & H4 approved

USA H1B Visa
1

I have H1 B & H4 Visa stamped for Employer A and currently working in USA. I got from offer from Employer B which I accepted and Employer B filed H1 & h4 transfer and new petition is approved. Now due to new circumstances is it ok if I reject the offer and decide to continue with Employer A. Does any impact on me & my dependents in future for stamping and visa related issue?

  Did I need to apply anything for my dependents who are on H4 for status change?
2

It is ok, you can reject. But make sure your payroll is running and your status is legal

You can talk to your present employer about the situation.