Ive Kited in Goa a few times now, used a 9m one day 14m the next,,, not sure how it is on the east coast for wind, I remember it being very windy... but I wasnt kiting way back when. One thing you do need to watch out for is all the oil from the fishing boats being parked up at night on the beach,,. Dont take a white Kite, you cant see it but theres oil everywhere.

There are a few local kiters on the west side, sorry cant help you for Chennai, but do remember there being wind down In mahabapuralm.

No, and you have to watch your step on the way down to the water as they use the beach as a twice a day toilet flush system. lol

Lakshadweep would be my pick.
They are a group of islands off the coast of Kerela.
they look phenominal. Expensive to get there by all accounts but worth every penny.
google Lakshadweep