The fireworks and ideally the projections are important to us, as son’s gf will be seeing for the first time. It’s been a long time since I worried about a “good” spot for the fireworks. 2 adults, 2 young adults. Do you have a suggestion for seeing both of these (10 and 10:30) that doesn’t involve setting up camp a long time in advance? It’s ok if we can’t get out of the park quickly (although of course that’s a good thing!) May 9, crowd level 5. As I said, usually we just kinda end up wherever and see what we can see, and we haven’t watched a nighttime parade in years, so this is a new priority to consider on this trip. Honestly, I have read articles, but find it complicated and overwhelming to follow their suggestions! Hopefully it will be easier to watch a second parade if offered.
You should never try to leave right after HEA fireworks imo. If the park is closed, go shopping on Main Street or something.
If you were considering paying for LLPP, you could consider booking the dessert post-party. The desserts aren’t very good, but the designated seating area is less stressful (not free of stress, but there’s a lot more room), and it gives you a place to sit while the crowds clear a bit. (Also, you don’t have to show up an hour before for the post-party - you can get there like 30 minutes, and you can bring snacks into the garden and sit before the show starts.)
Regular locations partially depend on how tall everyone is. 
. I am not very tall - best non-special places for me are behind trash cans (double are even better) or behind a planting bed with a fence. But I usually use Disney Math and save time, not money with the dessert party.
If there’s a second parade, it also means the park is open later. Last trip (before Starlight), we were able to fight our way over to BTMRR after the fireworks fairly easily (getting through the Hub can take patience).