Having your own car is a game changer in these situations. I think your plan is doable, but I’d probably reverse the order. Go to AK at rope drop (on a morning without EMH since you’re offsite). If you wanted to do FoP, get there extra early, but if not, Navi is an easy walk on while everyone heads to FoP. Since people are usually let in for the Pandora rides a bit prior to the official park opening time, you will likely be off Navi before 9.
Then take a leisurely stroll up to Safari, and ride with minimal wait. You can then choose to do a few other things at AK or just go back to your car and over to TL or BB by (or close to) opening.
You’ll be at the water park for the hottest part of the day, so just imagine chilling in the lazy river. I agree with you that you might be worn out by mid afternoon, so play it by ear.
When you’re done at the water park, you could head over to AK or AKL for a nice leisurely late lunch or early dinner, and linger in the AC. Maybe have a few late FPs planned at AK (I always like to do Safari in the morning and again in the afternoon because I see different animals being active). At minimum, it might be nice to go and sit there for RoL. Since you accomplished your goal of going on Safari early in the day, there’s no pressure to hit any particular schedule, so just cancel any FP you decide not to use.
