On HNI mobility part the causation is different 

Highest UHNI migration is BECAUSE we have created wealth & the 3rd largest GDP ( so UHNI can afford to buy residencies & passports) and not DESPITE that

People from Bangladesh and Pakistan would love to be mobile but no one wants them and they can't afford what we can

On 1st point, controversial though, I love the QOL in India  and precisely ZERO UHNIs are leaving lock, stock and barrel, they are doing for kids education, tax planning, business etc BUT still have a large portion of wealth in India