a few suggestions ...

Your plan is very aggressive. But 15 hours' driving is no big deal. We did non-stop drive from Detroit 10+ years ago.

Ohio's Seaworld is better. So skip the Orlando Seaworld. No need to go Island of Adventure either. Ohio has Kings Island .... I'd go Epcot instead.

Get into the Parks as early as you can and take advantaage of the FastPass.

Use priceline to bid hotels. Check go2orlando.com for additional attractions in Orlando.

Enjoy your trip!