As Clandestino says, the first part of your question is really not type specific. Have a think about how hydraulic systems work (this may invlove revisiting those dreaded ATPL manuals!). I think you'll answer your own question pretty quick.
And yes the Emergency Braking will be the only remaining system, as although it is part of the Blue system, once through the non-return valve it almost behaves as an independent system (although can no longer be replenished in this instance of course). This, according to Mr ATR, will leave you with "at least 6 braking applications." Not sure how much I believe that but I hope never to put it to the test in anger
Regards
D