Need info on H1b to H1 dependant visa conversion

Hello Friends,

Both I and my spouse are in H1B visa with valid stamped petition till 2019.

I am currently in India offshore location . My wife is working in onsite location and we are getting a baby soon.

Since i dont have an requirement to work in my wife’s current work location. I would like to go on H4 Visa and take care of her. Can someone clarify few things

Can she process H4 dependant visa for me ?

Can i travel in H4 Visa , will that impact my current H1B validatiy ?

Can i swap company after coming to U.S because i have H1B valid petition ?

Thanks You !!! Grateful to the people who responded.