I have a cube

That is 40mm x 40mm

Power and Volume DOWN would make infinitely more sense for “power DOWN” function.

disc disk

Got ‘em!

Laymen with no understanding here. Obviously there were other mistakes, all of which make sense to me on a rudimentary level, but the first mistake you listed was him using wifi? What is the more secure alternative? Or do you just mean sending data directly over a true wifi connection and not using TOR or another medium?