Thank you for your information. What do you use your FPs for and at what time?
Well, it all depends on what my plan is for the day really. Other parks have single rider lines for at least one bigger attraction. We have been enough that we don't need to sit next to one-another to enjoy it - we will always finish within a minute or two of one another, and we meet in the inevitable gift shop post-ride.
In MK, nothing has single rider, so strategies differ. For example, on my upcoming trip in mid-August, one day at MK, the plan is to have a pre-opening breakfast reservation at Be Our Guest, and be front and center for SDMT at rope drop (like right next to the ride), be off it by 10 mins into the day, make a bee-line for Space, then hit things like speedway (for you), or Buzz / teacups (for the girls/ladies in my family - I won't ride that one anymore), maybe Pooh... but my FP would be for say 9:45-10:45 on PPan (which (keep in mind) I don't need to actually show up to until 10:45 - giving me flexibility), then I might hit IASW or the carousel and and HM, (still with likely only a 15-20 min wait depending on what time I arrive) all on my way to my 10:45-11:45 FP for BTMR. Then I might grab a quick lunch in Frontierland (before the long lines develop), and check wait times at Pirates, while I waited for my Splash FP to open at 12:00. As soon as we enter the FP line for Splash (after scanning), I would be searching on my phone for FP#4 on something like Jungle Cruise to see what time I can get one for. Then it's high capacity shows, or a trip back to the room for a swim and shower, or even a hop to another park or something.
On an evening visit to MK, you are in the right framework. Lines will be long when you arrive and unless the park is open very late, the headliners won't diminish a whole lot. Understand which rides (and what order) make sense to find a balance between mileage and time in line, and hit the smaller wait attractions and shows in the earlier evening when it's crowded. sprinkle in what fits - but the mountains and SDMT will likely be the biggest time saving FPs to have at night. PP is really fine just once per trip for us. Also remember that once you see the fireworks once, lines will diminish briefly just before, and during the time they are in progress. We love taking advantage of that period to get slightly lesser waits. Like the SDMT during fireworks, timing the plunge from Splash Mountain with fireworks is an awesome sight as well - but much more difficult given the length of the ride and somewhat slow loading time!
Oh, and for the record - your FP for PP
WILL work with O'hana... Remember you have an hour from when the FP window opens to scan in. I can't sit in Ohana more than 45 mins before I'm stuffed out of my gourd! Service moves fast once you are seated. However, be early for your reservation - you will likely have to wait 15 mins or so to be seated after checking in!
And I will bet.... Your son that you have bribed will want to do Spalsh a second time after the first, but I do know that some have a hard time with thrills... you obviously know best!