It's not a romantic date ^_^ you'll have one with Jo next patch too x)! (also not romantic btw!)
Even if you don't pursue any sexual with Viv she'll still be part of the story <3
You'll be given another choice in the 2.70 patch which continues the Paul scene when Lisa & Paul both return home.
It's always the concern with these updates mate, I talked about this very problem on a post last month or month before that with each release there's always a chance that players might get very little content depending on routes
Oh dear that doesn't sound good, is this when starting a new game?
The saves for RPGM are stored locally to the game's www directory under (www\save) so to transfer your saves over you just gotta copy the save folder from the old ver into the new ver <3
It's setup to happen organically but the triggers for it are:
Paul Coffee 2 (On Blackmail Route)
Paul Shower 2 (On Blackmail Route)
Wearing Summer Blouse
Then you can just sleep as it'll proc during daylight on Lisa's house 2f
If you hold enter it'll play at x2 speed