You can skip songs just by playing another song, right?
One of the online players who does this: http://www.partyspot.cc/go/
Pausing would be possible by just playing a silent track (https://open.spotify.com/track/7hELzayNaLhTZa1we1wksc )over and over again til someone press play again which would play the last song at position it was when you paused.
Or do I miss something obvious here? (I probably am.. ☺)
But anyway, your hack is obviously awesome and really cool!