I was able to get everything working thanks to some advice from Russell. I replaced the stepper motor (idle control valve) but had all but given up on that being the problem because the vehicle didn't start afterwards.
Then Russell PMd me with this advice:
With the new stepper, the ECU needs to calibrate it and the ECU itself. You can reset the ECU by simply unplugging the battery for a few minutes. Then give it another crank. The first with out any peddle. Try a few times. Then a longer crank with a full peddle.
Hope this works, but who knows. There are a few systems at play. The next thing to check is purchase a vacuum gauge ($25) to test the vacuum lines for leaks. YouTube has good tutorials on how to check.
I went back, uplugged the ECU, waited a minute, plugged it back in and then followed Russell's advice exactly. On the longer crank, after cranking for about 20-30 seconds (which felt like a LONG time) she finally started! She had a rough idle but after a quick trip around the block to calibrate the ECU things seem to be running very smoothly now.
Thanks Russell! And of course everyone else (Jason, Chris) for your help as well. She's my daily driver so I'm glad to be able to get her back on the road.