We have a 9 year old and this is what we did this past January. We had a 5-day hopper pass.We were there for 6 full days. We did all 4 parks in this way. One day in each park and 1/2 day each on the fifth day in MK & Epcot, our choices to repeat. We used our 6th day to do non park disney stuff. We did downtown Disney, spent some time in the resort pool, and had a early PS for HDDR. We did our non-park day the last day because we were comming upon MLK week-end and knew the crowds in the parks would be higher. We will next time do our non park day in the middle of our stay to give us a rest day. We need one after 5 days of going all day. We too wanted to do Sea World but saved it for next year when we are going to add an extra day just for it.We loved AK. I would do that park and save Sea World for another trip, but that is just my opinon.My son loved all the parks.MK was still his favorite and MGM his least favorite.
Have fun!!!
Jordan's mom