The stock plastic spacers on most skates will compress or even crack if you do this a lot. This can produce a lot more stiffness in the skate, which may or may not be good, depending on your skating style and purpose. It wears down plastic runners fairly quick so rail sliders usually put on grind-plates on their runners. Any scrapes, gashes or other injuries incurred from wiping out and sliding on pavement. Normally this is done by raising the front and rear wheels slightly by flipping the frame spacers, or by lower the middle two wheels, or by doing both.
Rocker provides for much more responsive turning at the cost of some stability.
Skitching is simply hanging on to some moving vehicle and letting it pull you along. Potentially dangerous of course. It's bumpy, but with the proper stance and balance it's pretty fun.