I should probably mention some more developments that I didn't think to bring up previously.
Even when the car is cold, starting takes a few seconds and is a little bit rough. It'll rev up to 2k or so, and drop down over about 5 seconds. The idle is real inconsistent, sometimes it'll idle at 1100, sometimes at 900 or 1000, and sometimes at what looks like 800 or so to me. When it idles real low (800 is what it looks like), it idles rough like I mentioned. Replacing the fuel pump seems to have not fixed the rough idle, but instead just caused it to idle higher which prevented the problem.

I can't figure out any pattern or reason for the idle speed, it seems to idle at different RPMS randomly. It does seem like it idles higher, at around 1100 or so after driving for a little bit.
The idle ALWAYS somewhat rough, although when its idling close to 1000 RPMs the roughness is more like slightly tapping the gas over and over, and is barely noticeable. I don't really notice it unless I sit in the car, at which point I can kind of feel it and hear the engine revving up and down a little bit.
When the idle does go low, the idle dips aggressively, and nearly stalls the engine, as I've mentioned previously in this forum.

This is all I can think about right now. This didn't seem especially relevant to me before, and some of it I just didn't really notice at first. I tried not to make it confusing but if it is I'm happy to clarify.

 

Once it switches to closed loop, these are the idle numbers that the ECM should be targeting so on a engine that reaches normal operating temps, should settle down to 700 rpms. Possibly something i.e. vacuum leak influencing the idle speed.

 

Yeah it seems like the idle is too high, but when it drops down to where it's supposed to be, it idles rough. IAC maybe? I'll check that but can't imagine that would cause the no-start, especially because pressing the gas while starting doesn't change anything.
I do know that unplugging the MAF sensor (forcing open loop) fixes the rough idle issue.

While driving a little while ago I got a SES light that read H13-O2 sensor.
I just replaced this, however a previous owner did some weird stuff with the wiring on this car that might be causing problems. I'll look into that as well.

 

Highly doubt anyone can mess up a 1-wire O2 sensor however I can see someone that didn't know any better wiring a 3-wire heated O2 i.e. gang GND, +12v from distributor etc. May be worth investigating.