After lots of procrastination, nitpicking, more nitpicking, and then even more nitpicking, I'm happy to announce that the ceiling is now 80% done.
Sunday (the 12th) I did the white shellac (BIN) primer, and after lots of little touch-ups, nail hole filling, chip removal (and all the nitpicking mentioned above), I applied the first coat of white semi-gloss this afternoon. The shellac primer had taken a grueling 4 hours (roughly), but the first coat of white took 2 1/2 hours, which isn't so bad.
I will either do the second coat of white tonight around 10pm, or in daylight tomorrow afternoon. I am hoping that it won't need a third coat.
I'm also happy to say that despite the terrible condition of the ceiling, I'm pretty pleased with how it has turned out.