H1B Visa- Expired I797B

[softwareinme]

Hi,

I got my H1B visa picked in 2015 lottery, However the validity of the I797B was only for 6 months. Anyhow I had*my visa stamped on my passport with given petition. So I have expired visa stamp on my passport without travel to USA. Later my company applied for cap exempt for the extension of my visa and it got approved with a new issue of I797 B. After this*my work location changed, So my company had a LCA changed.

I have a hard copy of the expired I797B and soft copy of extended I797B after cap exempt. There are certain questions which I wanted to ask.

1) Is there a issue of new I797B after LCA Change.

2) As my wife also hold a H1B visa and she is about to travel in some time and I am planning to go on H4 dependent with her. Can I utilize my Old I797B or the Extended I797B copy *to have my cap exempt done by other employer while being on dependent in USA.

3) Is it legal to search job with old petition.

Thanks!!!!!

[scientist2016]

1) Yes
2) Yes
3) Yes

[softwareinme]

1) Yes
2) Yes
3) Yes

Thanks a Lot for the response.

[softwareinme]

1) Yes
2) Yes
3) Yes

Is it important to have the last I797B issued by USCIS for the Cap Exempt process?