The main five girls have more specific stats because they play a bigger role in the story. Bigger roles in the story means more dialogue, which means more dialogue options. Your relationship with the other girls will be simpler, so there's less variation in the dialogue. I'll explore the possibility of stats for them but it's unlikely since not every girl will appear in every episode.
Beyond that, every girl in the banner is an option. They will be side characters in the story but in terms of romance, you can make them your primary girl if you want to. If you only like 'the stripper,' you can choose to be exclusive to her if you want. You will still have a relationship with everybody else though, just not romantic and/or sexual.
Part of the reason the entire game is limited in terms of choices is because I'm limited in terms of development. So the choices I made available are what I think are the most important ones, which is whether or not to pursue someone. The next choice would be whether or not to deal with a character entirely but writing out entire characters would change the structure of the entire story. Every girl introduced will have a part in the overall story whether or not you pursue them.
There are 11 girls to pick and choose from. You can pick none of them if you want. I think it's a reasonable compromise considering what I'm capable of.