make any sense to me as to why I would have the fuel delivery problem
> again. I suppose it's possible that I got a bad relay, or that my fuel
> pump decided to bail on me at a very ironic moment, but the symptoms
> that I fixed in paragraph two returning exactly as they were in
> paragraph one, I find strange.
>
> Does anyone have any ideas, or seen this before?
Yes. You don't have a fuel problem. The symptom of stalling when you take your foot off the pedal is because the computer is not adjusting the IAC (idle air control) motor properly, thus not allowing enough air into the throttle body when the throttle blades are closed (foot off of pedal). That could be due to a number of reasons, one of them being a weak battery.
Put in a fresh battery, start the vehicle, and then measure the voltage across the battery terminals. You should read around 13.8V - 14.0V, in which case the alternator's doing it's job (if you only read about
12.5V-12.6V, then your alternator's shot). Do NOT use the old method of disconnecting the battery while the engine's running to test the alternator... that works fine for non-computer-controlled engines, but the electronics really don't like dealing with the voltage spikes that the alternator produces (which the battery absorbs and smooths out - think of it like an electrical shock absorber).