I think you've gotten some great advice. Many people, because multiday tickets save a few $ (e.g. fourth day at Disney is practically free), etc. often will focus on Disney exclusively, Universal almost exclusively, the Seaworld family of parks exclusively on different trips. In reality, though, everything is close enough and you can do whatever you want (mix it up -- but you will pay more). We usually mix it up. There is so much to do in Orlando, though, that you will need to pick and choose activities and won't get to hit everything. This is just a great excuse to come again, though, in my opinion. I do love Orlando -- such a great place to have fun with your kids.
People too who don't want to do much driving will often stay onsite at Disney, especially if they are doing mostly Disney parks, as this makes it very easy. They will pick you up at the airport, take you back, and have a great transportation system for getting around. This is in their best interest too, as this is where you'll spend most of your vacation $s. And they have resorts for almost every budget. The resorts are really pretty nice too. The Downtown Disney hotels offer the next best transportation to Disney parks with shuttles every 30 minutes to all the different parks. Universal onsite hotels are on the more expensive side, but many people will even do split stays and stay here for the front of line perk that is available for rides except for WWHP even if they are only going for one day. Universal hotels also offer early entrance to the WWHP area.
Another popular option is renting an offsite condo or home. This is great for families who want more space, a kitchen, laundrey, and for large groups especially is by far the most economical option. Typically a car is necessary with this. For a short trip, I think a hotel is fine, but I really like this option for longer trips.
You have six things listed (all which are full day activities) and five days, so just pick one thing to drop. Given your emphasis on Disney (We love Disney) onsite or downtown Disney accomodations sound like a great choice. I'd be inclined to keep your four Disney days too, as your fourth day is practically free. If you want to do both a day IOA and Kennedy, though, you could decide to skip one of the Disney parks. I wouldn't try to see two in one day if this is your first visit. Each once has a lot to offer/do. If you go to Kennedy, the most economical and most flexible choice would be to rent a car for the day or are you planning on renting a car for your whole trip? If you already are planning on having one you are all set. You can rent a car for a day or two right Disney property. There are some transportation deals I've sometimes seen posted between Disney and Universal/IOA that many people use who are mostly focusing on Disney, but don't want to pass up seeing WWHP// there was one where I think transporation and tickets were included together, posted just a few days ago. Driving over is definately an option too.
Have a great time / whatever you choose.
We are doing a five day trip too, in two weeks // staying at an offsite condo with a large group and have a car:
Our picks this time are:
Sea World Day 1
MK Day 2
Kennedy Space Cener Day 3
Disney Hollywood Studios Day 4
Sea World Day 5 (Our favorite park and we have season passes)
Oh and if you are thinking Downtown Disney, you might want to check out the link on post #113 on the Holiday Inn Friends and Family offer that Shelby Jones lets disers use. The Downtown Disney Holiday Inn has been recently remodeled and gets great reviews. Take a peak on trip advisor. I know I 'm thinking of staying there on my next mini trip in 2012. I used Shelby's discount to visit family in NJ last summer / best rate I ever got for the Crown Plaza there, and I've been doing annual trips out there for more than 20 years. Link:
http://www.ichotelsgroup.com/h/d/6c...Uk70%3D&cm_mmc=DCE-_-FF-_-20090821-_-AM159051