Is a private viewing pretty much a lapdance that goes a little further?  any chance on 2 cups if get too exited early?

YMMV more in this category than in others.  Each PV provider sets her own standards, and they vary widely!  Some PV's are just that -- look but don't touch.  Others are MUCH more intimate.  My advice is to sample, learn what the rules are by asking, and patronize those you like.

...there are apparently different versions of it (e.g., PV+, Expanded PV, etc.).

You name it. Everything from no touch to FS. Ladies may use the PV label to divert Ellie, and to weed out the riff-raff. The ultimate YMMV. BTW, I am a huge PV fan. A big part of the fun is the YMMV part.  In my pathetic life, it sometimes feels like an unexpected score.