I’m a big planner, too. I have two daughters, who are 2 years apart in age, and we have been going yearly in August, since the little one has still been a baby.
Here’s what worked for us, when the kids were little:
Having them be part of my prep work as to which rides to target, using first person
YouTube videos, so they can decide what looks exciting and what looks scary. Also, have your kid help you prioritize rides into “absolute must-dos,” “ok to dos,” and “I’d rather nots.” My kids also love to be part of the prep work.
Bring lots of snacks (somewhere in the website it says to not bring in food, but they tend to be really lenient about this, unless you bring a huge icebox with stuff—that’s not allowed). I have my kids help me pick out snacks they like in the store.
If the kid is small enough (and not insists on being too old for that), an umbrella stroller can greatly increase your mileage and also be used for little rest periods.
My plans are usually precise to the minute (with several versions, depending on ride closures) in the early morning and then get subsequently more lenient throughout the day to account for unforeseen hiccups—as a result we do get a ton of stuff done while minimizing stressing out over it. In order to utilize that first “golden hour,” we actually “train” getting up early. I wake my kids and have them eat breakfast according to our Disney-schedule during the week leading up to the trip to get them used to getting up early.
Remember, you can still use your Maxpass to pull Fastpasses, while being in your hotel for the midday break. I predict that you and your family are in for a fantastic time. This is the perfect age for a first Disney visit: old enough to not get too overwhelmed but young enough to be fully swept away by the magic of it all.