You can term Kashmir what ever you want.. But for Indians it as much a part of India as Balochistan is for Pakistanis.
Just like how your terrorist die every day in Kashmir.
Those 600 million Indians are not poor because of Kashmir.. Nor will they become rich if kashmir is given to Pakistan.
When Britian was on height of its power.. And the sun never set on British empire.. More than half the Londoners use to live in slums.
In a capitalist economy.. Socio economic rise is gradual...because of trickle down effect.