Well, "sink" and "source" are generic expressions for describing a vector field. "Acquisition" and "restoration" would be treknobabble to specify the nature of the vector field in question, and the operations performed on it. Sucking and blowing need not be part of the workings...
The Enterprise is propelled by matter-antimatter reactors.
(a very concise statement)
Actually, that would probably be as far from concise as can be, as Spock is selectively describing the one aspect of the propulsion system that would be of importance to his plan of blowing up the ship. It's no different from him saying that a car is propelled by gasoline if he intends to make a big fire and has no interest of propelling anything anywhere.
As for the spheres at the aft of the nacelles I guess it's not too farfetched to assume that those are the nacelles' antimatter "pods" that had been repeatedly mentioned / suggested in the series.
Possibly. But other explanations would more satisfactorily explain the absence of these spheres in certain situations: either just from the early versions of the ship, or then (if one goes the TOS rather than the TOS-R route) from certain stages of the ship's mission. Antimatter pods would always need to be there. Fancy exhaust filters would not...