Quick release back wheel?

Yeah, i've read sheldon saying it's fine fixed, if you do it up tight enough. You can get QRs HELLISHLY tight, so tight i had to remove my seatpost and use it as a lever to get undone after a puncture once. (but of course sheldon does not condone brakeless riding under any circumstance, let alone with a QR skewer which is undoubtedly inferior to tracknuts)

He's actually a lot more specific than that.
http://sheldonbrown.com/skewers.html

...The exposed-cam skewers are generally OK for vertical dropouts in back, and for forks with "lawyer lips", but should not be relied on with horizontal dropouts or plain forks.

...Good skewers have a serrated steel surface to bear against the outside surface of the frame, but most of the "boutique" skewers have soft aluminum parts in this position, presumably to save weight.

The aluminum "teeth" are too soft to get a good grip on the dropout. Since the chain pulls on the right side of the hub, where the acorn nut commonly resides, this type of skewer is almost always unsatisfactory for use with a frame that has horizontal dropouts. In addition, "boutique" skewers generally have (yuck!) aluminum threads, vs the steel threads of the two-piece acorn nuts. These are much easier to strip.

As a result of these design flaws, "boutique" skewers should not be used on frames with horizontal dropouts, nor on older forks that don't have "lawyer lips."