I'm glad you liked it!
The relationship stats for the girls cap at 50pts. Currently Ruca has content mostly up to 40pts, although the night scene has a few options that unlock at 50pts.
You can find all the scenes and their requirements in the walkthrough located in the phone's setting menu (the middle icon). It's a bit messy at the moment, but I'll be making it more understandable in the next version. :)
As for updating the game without re-downloading the whole thing, it's currently not possible. Once the game becomes heavy enough I might start releasing separate "update only" packages.