All this stuff looks cool, but what the heck is a pin jack cleaner?

Looks like it's a cleaner for the phone screen that plugs into the headphone jack and hangs there. At least, that's what Google Translate on the Japanese description suggests.

That's a lot of pieces. Also, what cut do they use? The "everything fits" cut, the "incompatible except where right" cut or a gimmick cut?

I find it kind of funny how Klavier is on everything despite doing... basically nothing in the entire game.

That makes sense, although it almost seems like a bigger hassle to always have that thing attached than to just clean your screen at home every once in a while.