With constant speculation about the value of bitcoin,
they can speculate all their want, it has no effect on reality!
for example if I have some bitcoin balance and you guess it 1000 times it won't change how much I have!
China claiming to ban exchanges of bitcoin,
this can temporarily cause some drop but most of that drop has already happened so it won't be much anymore. as they say "it is already priced in".
and some banks trying to create their own blockchains for their countries,
they can create all they want, but in the end it will be a centralized thing just like fiat and it will never have any effects on bitcoin and its usage or its price
What will happen to bitcoin if this become true? Will it be still used ? will it not be worthy anymore ?
if you think some random news about a "service" (exchanges) is going to affect bitcoin's usage or its price then you haven't really understood what bitcoin is.