Some tips for Okinawa

Hi everybody,

 
 Just wondered if I could pick some brains about Okinawa?
 

I am heading to Okinawa in last few days of September for 7 days travelling with my wife and two children (7&10).  We have rented a car from Naha airport and have an apartment in the region of Fuchaku Beach in the Onna area.

 
Was planning to do just a couple of activities (Himeyuri Monument and Himeyuri Peace Museum, Cape Zanpa lighthouse, Nakagusuku Castle, Churaumi Aquarium ) and spend much of the rest of the time visiting beaches/ making it up as we go along.  

My daughter has decided Gesashi Uppama, Gushichan beach and Sesoko beach are must dos. I quite like the look of Odomari beach but essentially sand and sea is pretty universal so I can skip it.
 
Rough idea
 
·      Monday arrive – drive to apartment (flight lands at 2:30 pm so nothing that day)

·      Tuesday Churaumi Aquariam, afternoon at Sesoko beach on way back.

·      Wed Cape Zanpa Lighthouse, zakimi ruins, maybe down to Chatan/ American village for afternoon of eating etc.

·      Thurs Nakgusuku castle then ???

·      Friday Himeyuri peace complex and then afternoon at Gushichan beach

·      Gesashi Uppama beach (seems quite far out of the way but looks peaceful)

·      Sunday – stay close to home, Cape maeda for snorkelling?? Okinawa Cave)
·      Monday flight back at 2pm so drive back to airport after check out

Just wondering if this sounds feasible or am I condemning the family to traffic jams the whole time?
None of the distances seem huge but the traffic sounds dreadful from what Ive heard.

Should we be taking one day for the Karema islands? They look beautiful especially Zamami
Am I doing us a disservice missing Naha out?
 Would we be advised to get back to Naha early that last morning and kick about for a few hours before our flight
 
Reading a lot about jellyfish is this fear overblown?
Do we need neck to ankle type swimwear or will rash tops and shorts be enough?

Is there anything that jumps out as a glaring omission? My kids want beach, my wife wants relaxation after Tokyo, I just want everybody to have a good time (and some cold beers in the evening)