Agreed, it’s a great game! Two of your questions have community answers already:
- Infinite mode: there’s a mod, Continuing Semesters, that lets you carry a finished save into a new semester with the same girls (disclosure: I made it).
- Sharing characters: the community Discord has a channel where people post their custom characters, so no need for a Google Drive.
Feel free to join us: https://discord.gg/BHzA7M5NgB