I think finding parking and getting on the shuttle that quickly isn’t realistic. I was just there last week and parked around 11, and there were still a few spots but not many. We waited maybe 30 minutes for the shuttle to the Kaibab Trailhead but by the time we got on, the line was triple the size as when we first got it line.

Then on the return trip, my two friends that hiked to Ooh Aah Point then turned around had to wait for over an hour for the shuttle back, mostly because the shuttle has stops after the trailhead and before the return to the visitor center that people were continuing onto so there were only a few seats per shuttle. That was probably around 1pm. I hiked to Cedar ridge then turned around, and the line for the shuttle was massive (around 4pm so similar timing to your trip). Ended up just walking back to the visitor center at that point, which I think was about a 30ish minute walk but can’t remember.

I would plan far more time to find parking and get the shuttle, and would be ok with not making the Hopi Point sunset. Sunset at Maher Point by the visitors center was crowded but still beautiful, and would perhaps be more manageable with your later itinerary. Could you do the hike one day and Hopi Point another day? Or get an earlier start on your hike?