All of your issues with this game are because you are obviously not familiar with RPG Maker games because:
1) (Why do you even put both a dot and a bracket?!) Every RPG Maker MV game is switchable from windowed to full screen and vice versa with F4 as the creator already answered.
2) If the game's volume starts at "full blast" then your system volume was high to begin with, which is not the fault of the game and what has porn anything to do with anything in this matter?
3) Every RPG Maker MV game fast forwards dialogues and cutscenes by holding Enter and automatically stops at a choice so if you make a choice inadvertently while skipping dialogues is because you spam Enter instead of merely holding it down until fast forward stops at a choice to make.
As for your statement about "most games use Ctrl to skip dialogues", this is actually only Ren'Py games which do.
5) This was actually a good suggestion and I think the creator accepted it because I didn't have to answer 100 questions when I played this game, I only had to pick my lore background exactly as you suggested. 😉