I think I may have stumbled onto my problem. I was researching and found this picture yesterday, listing common shorts in our pickups:



From my problem described, I looked at number 8, the canister purge solenoid. It makes sense to me that the problem may be vapor lock (fuel pumps both stop pumping fuel when there is air in the lines, has happened after sitting for not long and then restarting, bleeds itself out eventually, etc.

The wires looked good but I pulled the purge valve solenoid and it looked completely closed, which I'm not sure if it should be when the circuit is 'open'. Also, I can rotate the connector end of the solenoid and the pins rotate, which probably shouldn't happen.

I took a vacuum connector and pulled and bypassed the valve, and took her for a drive. I feel like I've gained a little more smoothness in the powerband, and she hasn't hiccuped on me yet, though the drive was only about 15 miles.

I'll keep everyone posted, but if it won't start again, I'll try to get a gauge on it.