Hi AvidFlyer1990, and welcome to flyertalk!

There are a number of threads already related to your questions. Try taking a look though them. The first one is a long thread, but there is some discussion about best use of JP miles. The second thread is a discussion related to service quality on Jet.

http://www.flyertalk.com/forum/india...ions-here.html

http://www.flyertalk.com/forum/india...eir-touch.html

As for mileage running on Jet (or AI for that matter)... well I have to say I don't see that question come up much. I wonder why (i.e., take a look through the first thread mentioned)