I probably needed practice taking the motor out and putting it back in again anyway. You can never be too good at that. 

It's 11:30pm, the car is all put back together, the clutch actually feels like a clutch now, and all is right with the world. All things considered, not too bad of a diversion. 

As suspected, the culprit was me using the throwout bearing sleeve from the four speed instead of from a five speed. Luckily, Brian Zana up in North Las Vegas happened to have one, so I went up there at 6pm this evening, and by 10pm or so I was back in business. It was like one of those credit card commercials, except without the "priceless" part--

"Replacing your throwout bearing with the right one: Two minutes."
"Pulling and then replacing the motor to get at that throwout bearing: Six hours."

Builds character, I suppose. For the curious, here's the actual culprit:

So now we take it in for an alignment tomorrow, and if all goes well, I'll be on the road sometime in the next couple of days. Hopefully that's the last time I'll have to pull the engine out for a while...