"Instead of staying at the same spot all day, like you would skating or BMX'ing, you just bomb **** and hit what you feel like hitting along the way."

You just described the riding style of the 80's, full tilt balls on ripping....... with tricks.
I've done stairs on my SS, real slow mind you. Now if we had some bomb-proof rims.....hmmmm

I still say Traffic Jumping...... little ramps set up all through the city zones where messers work.
Kick ramps that will allow you to boost over the corner, from roof top to park garage. You KNOW someone out there is sick enough to do it. Freerunners are all over the buildings, freeriders all over the mountains, now it's time for the speed version of urban freeriding, at speeds that MTB can't get to..