Milardo:
Zoom Player does not encode video, it's only used for playback.
I haven't tried NSV files in a while, Zoom Player is directshow based and supports easy integration of 3rd party filters, so if there's a filter that can parse NSV (I can't recall off-hand if LAV does it) then Zoom Player can play it.
Zoom Player can be skinned, both in windowed mode and fullscreen navigation mode. There are quite a few existing skins out there (
http://www.inmatrix.com/skins.shtml) and using the latest betas, you can use custom background images or patterns for full screen navigation (samples:
https://www.facebook.com/zoomplayer/...30936590321649).
You can make Zoom Player portable, but there are a few limitations, for example, not all directshow filters work perfectly well without being registered with the system. ZP can create the filters from the DLL without having to register the filters with the system, but then their property page becomes inaccessible.