Probably from the intake pipework I think it comes from the right hand crankcase. Somebody with more technical knowledge may be able to confirm or deny though.
No need for a crankcase breather as most people with 350Z's keep a closed loop, not sure what effects this engine has on venting it too atmosphere. (I did this on the Subaru)
tru mate suppose you could as many feeds in as you wanted!!! no i dont think its needs a breather filter as it breathes through the air filter !!! (i think)