Hi there!
You miss the tutorial Polaroid if you skip the into of the game.
No idea about the headphone jack thing, sorry!
Butt flash bug will be fixed next update, thanks.
There are a couple of small easter eggs if you fail Sucrose's quiz by picking all the 'very bad' options, and if you bring Mona Eula's panties and then visit the peephole after the festival.
Glad you enjoyed the game, and thanks for your comments!