It would be nice to have more influence over the exploration. Being able to give the girls an item to take with, or a general area to focus on, or send them out in pairs for safety, etc.
Items you find on an expedition or exploration will appear in the cabin before that character returns. And on a humorous note, the stereo continues to play during the gameover screen.
Also more interactions between them based on their relationships would be interesting, such as negative ones being a potential outcome.
Oh and a possible Archive that keeps track of scenes you've read and done. The gallery is nice for being able to see the pictures, but being able to read their corresponding posts would be even better.
Enjoy the game a lot overall though :)