I know that I'm not REALLY using the full graphics capability of the nVidia card in my Mac (and that may take an upgrade of VBox to fix it for the Mac platform).
Its my understanding that VBox uses its own video driver (i.e it won't be using your nVidia card as such) which is one of the reasons why Compiz or a 3D desktop can't be used.
I'm still a neophyte for Linux so it's nice to have things on one platform
I hear where you coming from - once your confident with PCLOS I'm sure you'll take the plunge and do a "grown-up" install (smiles wickedly)
As for swap space its rarely used nowadays in most modern setups but how VBox access/uses swap I'm not too clear.
As I say, if things are running A-O-K I wouldn't bother tweaking too much (if it ain't broke.....)