Executive MBA

The institute is affiliated to In Academic Association with Southern, New Hampshire University so it's not regulated with UGC and AICTE, to having degree from such institutes may be good by quality wise but when you apply for a govt. jobs the certificates may not be valid. If you are searching for UGC, AICTE approved university. You can find institutes in following link:
http://www.mbadistancelearnings.com/top-ten-distance-learning-mba-colleges
I hope this will be of help.

I would recommend you doing executive MBA. You have more now than 3 years of work experience. You have better chance of making into good MBA colleges in India. You just now have to prepare for entrance exam and Interview process.

Yes, it is a good one and you have a compatible experience for it and MBA is a practical subject.

I would suggest you to pursue PGPX from IIM A or EPGP from IIM-B. Both are equally reputed courses to pursue to help you kick-start your professional career.

This has been already answered before. I am reproducing this as:
From knowledge point of view, it's good. From job placement perspective, no. It depends on your own performance and you can never get salary at par with any full time MBA even if it is from Great Lakes.
Checkout this answer on shiksha:
https://ask.shiksha.com/is-there-any-difference-between-students-who-are-doing-part-time-mba-and-regular-mba-during-campus-placements-qna-4122488?referenceEntityId=4122606

Yes, as for executive MBA, no same field experience required. However, since there is no placement for executive MBA you may not find job on your own and you may need to do a completely start afresh.
You should take a decision considering all these factors.