The answer to most of those questions is that this game is a shitpost originally made in 3 hours and slightly improved since.
I might spend more time on improving it more soon though so I might fix some of those things
Saves are automatic, I should add a message at the start explaining how it works. There's no manual save because well it's a 5 minute game
(also it's intentionally not subtle because I do not trust gamers to understand the message and I don't want to accidentally make people think the point of the game is to endorse Hogwarts Legacy)