Shifting without using the clutch isn't going to hurt a damn thing unless you're a ra-tard and start grinding your gears together like a whore's teeth in church.
I've driven over 60 miles with a snapped clutch cable without ever using the clutch. When you rev-match, the gear you're coming out of and the one you're going into have the same RPM, thereby eliminating the need for the synchronizer's friction surface to "speed up" the next gear so the blockers can move over. As long as you're not some namby-pamby, limp-wristed mouthbreather who can't seem to pull the shift lever hard enough to get it into gear, you're typically not going to have any problems grinding.
The whole excercise is pretty useless in a normal car anyway - whythefuck would you want to drive without using the clutch? That's what it's there for. However, if your clutch cable ever snaps while you're out with your buddies at some circle-jerk street race in the middle of nowhere... you can pat yourself on the back for your brilliant foresight and wisdom in learning to drive without it.
Paul.
