I there any BTC exchange in the world which is legally bounded not to take people's bitcoins. E.g. if a person in the USA uses Bitstamp or Okcoin, is there any legal obligations on these exchanges to give you your BTCs? Can a foreign exchange e.g. a Chinese one take a on Chinese person's funds + BTC away?

Anyone looking at the charts will see whales pushing the price down again and again. Is this good for Bitcoin's PR?

Its amazing how a dip on a western exchange with little volume affects the big chinese exchanges!!

It takes long to transfer BTC. These changes happen very quickly so it can't be arbitrage . Sometimes there is always a gap in prices. E.g. There was a time when Bitfinex was always higher than Bitstamp by a few dollars. If arbitrage was the answer then why that gap?

If the price changes on an exchange then the change is seen very quickly on other exchanges? Why is this? Do the exchanges ensure this or the users? Or is it bots which access many exchanges at once?

I can't see users reacting so quickly to a price changes and actually implementing those changes on other exchanges.