Thank you very much, glad you're enjoying it! The next character to be added will definetely be her sister, though girl variety is something that this game will probably just lack. Given the amount of time I spend on each one. But it's something I keep in mind myself also.
Yeah the club vip rooms will be expanded with new girls and more sex stuff. I'll talk about it more close to the time though
Thank you! It may be awhile before we see that kind of content, but it's something I'd probably do for each character. Though you might get some hints of it rather soon
I didn't make the save system, so I can't say for sure. But it just looks like the save doesn't have any actual data in it. It's rather shorter than a typical save file. Unfortuately I don't think it's something I can fix for you.
You probably have to unlock the next outfit with reward points. Just ask for her a reward in the kitchen and select the outfit option. If that isn't working, let me know.