Would like opinions on MK, our Day 1, 2/8, CL3

Thanks for any opinions/suggestions for this our 1st day. We are a party of 5: DH, me,DS & 2 DGSs, ages 9 & 6. DGS9 will have a DAS in case we need it. We’re arriving the late pm/evening on Tues. 2/7, staying offsite. Checking in to Poly on 2/8. Plan on arriving early to Poly, picking up my scooter. Have an 8:10 O’hana breakfast then will head over to MK.
Planning on 2 days at MK, 1 at each of the other parks, no park day at Disney Springs with HDDR that night, and a day at Sea World.

This is what I came up with for Day 1 at MK. Don’t know if I’m timing the DAS return times correctly.

http://touringplans.com/plans/print?id=2216157

I think that looks like a great day! Not too packed, and the flow is good.