Hello Tom!
I loved your icon! Good job! Regarding the list of commands, we made an update to our visual novels templates so I'm not sure which are the ones from our past games and which are the hotkeys they have. I believe the mouse right button shows/hides the UI in all games. There is no key to pause it (maybe ESC to show the menu?) and no keys to take screenshots - Steam provides a feature for that but it's not a part of the game.