there is no gallery which is a little bit of an issue because some scenes only happens once.
for example when you get a titty job for the first time by Hinata she will become incredibly horny and go to the bathroom to masturbate and you're supposed to follow her and then make her suck your cock and it's really good scene and it only happens once any other time you try to get a blow job it will not be the same and there's a few scenes like this.
for the second question? I'm assuming all female characters will have at least one sex scene but I'm not the developer so I don't know