I think you're probably right about APs vs people with dated tickets. We have APs and have done all the rides and shows multiple times, so the Grinch was a priority because we can't do this meet on another trip. If I only had regular tickets, I would be prioritizing the rides. Although with the requirement that only one party member needs to hold the spot in line, I imagine the number of people who wait the whole time is fairly small. I could see a party of 3 or 4 rotating who waits while the rest of the party goes off to enjoy the park. I agree meeting at 8 would be good. Adding another Grinch (or two) would be better.
I was very tempted to book the breakfast. For just me and my daughter, the price would have been almost reasonable. But then add in two teens paying adult prices, and it blows up the budget. For the Wholiday Spectacular, we went to an afternoon show and had no trouble getting in. I had never been back there before, but that theatre is huge! My daughter thought it was fantastic. My sons, on the other hand, are now team Grinch because the Whos were so annoying they had it coming.