We tried to RD Pandora twice in February, unfortunately we arrived later then we wanted, and it was about a 90-120 minute wait instantly for FOP while NRJ remained a walk on experience. If you could take advantage of the EMH, it might be worth trying to get on FOP then. I was lucky enough to snag FPP for FOP when AK extended their hours, I would just say to remain vigilant, that a FPP might pop up if you are constantly checking! Or if possible, you could break your party into twos, and possibly get overlapping FPP times.
Also, I hope your daughter is brave enough to experience it! It is without a doubt, the best attraction on the WDW property, possibly all of Disney.
And as you've said, if you can only snag a late FPP or FOP, it would still be worth it to avoid a 120+ minute line, when you can take advantage of a short line at RD for NRJ, or ride it later in the evening after the first show of River of Lights, etc. Waiting only 10-15 min for FOP, but having to wait the other rides - KS, EE, Dinosaur - while not ideal, isnt the worst compared to 120 minutes. If I could only do 3 FPP for AK, it would be FOP, KS and EE/Dinosaur. I prefer EE, but the queue isnt bad if you do have to wait - while Dinosaur is a pretty meh queue at best. Also, if you do arrive a little late to EMH, you could hit up the rest of the park while everyone else goes to Pandora and still walk onto rides such as EE/Dinosaur, or minimal wait for KS.
EDIT -- I have now read the rest of the thread, I am happy you got somewhat early FPP for FOP! I really think its a ride worth planning your day around. And after riding it a few times last trip, I would be willing to spend 100 min in line for it easy. Only other ride worth that time in my books is Indiana Jones - though I've never rode Radiator Racers, so that might be up there too.