New symptom just manifested itself, and when I say 'new' I mean I haven't noticed it before, not that it necessarily hasn't happened before.
I just topped off the tank. It took 12.6 gallons about ~8-10 miles after the gas light first illuminated. Again it took about 30 seconds of running the starter to fire up, and it idled a little rough until I put it in gear. Driving off from the gas station, I noticed the fuel gauge as pictured. Is the fuel level sender vacuum based? Everything else seems consistent with a vacuum problem. Just for due diligence, I did swing back around by the petrol station and confirmed there was not a couple gallons of premium on the ground, no giant flammable puddle in the car, etc. I drove another 6-7 miles home and no increase in fuel reading.
I got some really good troubleshooting advice already, but before I go running all that down, if this indicates anything more specific and might save me some time and or money, I sure would appreciate it.
(Click image for big version)