No, not yet
no
Yes.
Black and White haven't been released yet...
Yes.
no sorry
It was Pokemon Black 2 and White 2. The only Pokemon game that had a sequel.
no
There is not an event to get Keldo YET.
It has not yet been announced when Keldeo will be available for download in Pokemon Black Version and Pokemon White Version.
Yes. However, it is yet to be released by Nintendo.
It is an event pokemon, the event for which has not been run yet.