Hey there!
1) it's one of the events that appears only once in a playthrough
2) it's bugged event, will be fixed next week, sorry for that!
3) saves are stored outside of your game's folder so you just delete the previous folder and download new version and the save will stay
4) GH is still in development and DP and TP animations will be filled soon, together with those variables
And thanks for playing, I'm glad you are enjoying it! <3