Thanks for the feedback! There are narrative reasons for a few of the things you're wondering about, so they'll become more clear once you get into the characters' routes.
Marion is not meant to be a 100% self-insert character. She's more like a pre-created character that you're able to role-play through in-game choices to a certain extent. She is canon bi/pansexual, for example, and though that doesn't play much of a role in the routes in which she romances men, it's still who she is.
I wanted to write a story with a protagonist who has a strongly-expressed personality and a clear background. Because of this, she will have interests and preferences that differ from the player's. This is true of every visual novel, even the ones that actively encourage self-insert characters. It's impossible to write a narrative that works for the preferences of every player, so the best I can do is try to be true to Marion and her story.
The dancing transitions are definitely something I'm still working on, as I'll be working with another coder who is more skilled at Ren'py animations than I am during full development.