Okay, well i got the pump lock ring back on, finally. I just took my time alligning the pump in the tank. Once seated the ring fit a lot better. I sprayed the ring with wd40, put pressure on it with two flathead screwdrivers and wiith a bit of encouragement it grittily spun clockwise back on. No tank dropping required.
So, i buttoned everything back up, reconnected the positive battery terminal and primed the pump with my key. It fired up after a couple cranks.
Fuel pressure at idle: 39 psi
Nice!!!! I checked for fuel leaks, and took a test drive. Night and day difference. More power, no sputtering and no sign of any bogging even when flooring it up a nearby hilly street.
I'm cautiously optimistic that the hose being detached was the source of most of my issues.