I really want to second this! Great suggestions. I feel the same. The game is waaaay to unpersonal at the current stage and a management sim like this depends on personality. This is really something you have to work on to make the game more lively. For now it would really be enough if you add more information to the girls, A skill system like he mentioned it, would be amazing later on of course. Also it would be nice to customize your idols better. In the finished game it would be nice if you have a full system to customize them.
But yeah, as for now I think the game needs to get more personal and lively and that would be a good way to get there.
Keep it up guys!