When cold, the engine runs off of a pre-programmed calibration in the ECU. At some point as it warms up, it changes over to a sensor feedback scheme, which does, in fact, involve the O2 sensors. So, to the question, could bad 02 sensors cause this, the answer is yes, they could.
Is it the most likely issue? Well, I like what you have done so far with chasing down the more probable causes. You changed out the MAF which would have been one of my first thoughts. I assume you got a new MAF? Junkyard MAF's can have issues. I bought a used MAF from someone on Ebay and it looked nice and clean but it was actually bad. Just saying, if you bought a used MAF you shouldn't rule it out yet. I liked the idea of the IAC, easy to change and not very expensive, same issue with used ones though.
You have ruled out fuel pressure. Did the readings follow the profile, that is, did the pressure drop slightly when you reved the engine? I'm trying to decide if the fuel pressure regulator is in play.
You have ruled out vacuum leaks. That's good, that's a tough one.
You replaced the plugs. Were the old ones uniformly similar in wear and color? I like your thinking on this, could be weak spark. So, that puts the coil and ignition control module on the table.
I think somewhere along the line I would get the ECU on a bench and check for bad capacitors. That's a freebie to check without actually replacing an expensive part on a chance.
Or O2 sensors. They are not particularly expensive, it's more the work of replacing them.
Assuming you replaced all the parts you did with new parts, and assuming the fuel pressure followed the profile, I would do the following:
1) Check the ECU for bad capacitors
2) Replace the O2 sensors
3) Replace the ignition control module
4) Replace the coil
It's too bad you don't have codes to rule some of this out without buying a bunch of parts. But, I do like the ECU bad capacitors for this... there was been a rash of bad capacitors reported here lately and they will eventually fail with age. Good Luck!