I guess the best answer to that question is of course a BIG NO! Granted, China is a big contributor for the rise and adoption of Bitcoin and they are primarily the country involved with Bitcoin mining due to very cheap electricity cost.
Now, the Chinese government has its own agenda and I think in the long run Bitcoin can be running against those agenda so they are now thinking of slowly disengaging and disconnecting their citizens away from the cryptocurrency platform.
I know that whatever China will decide on the impact can be heavy on the market and this is shown with the recent decision banning the ICO projects and the unconfirmed total ban of Bitcoin exchanges though it is still a rumor and nobody would want to confirm.
Can cryptocurrency still go on and have a very optimistic future even without China as part of the equation?
for your last question the answer is YES. you can see, for now so many countries other than CHINA prohibit and banned any transaction that uses bitcoin as a means of payment. but whether the bitcoin is dead, of course not. the decline in bitcoin prices because of it, yes it is certain. but it does not make bitcoin disappear and die. internet and technology are the main factors of the existence of bitcoin in the world. so, as long as the internet exists I think bitcoin will still exist and will definitely grow in technology and system