Hi Kristian!
Thank you for visiting the Moms Panel!
I think you have made great choices for your four days at the parks. I love visiting Epcot, and there is something for everyone at every park, but possibly a four-year-old would prefer the other parks. I think you will all enjoy Magic Kingdom park, and there is more than enough for your two days there. Animal Kingdom and Disney's Hollywood Studios will also definitely keep you entertained.
Be sure to pick up a Times Guide as you enter each park for details of where you can meet the characters, and the entertainment schedule for that day - including parades and shows around the parks.
Have you considered making a dining reservation for character dining whilst you are at the parks? I would recommend
The Crystal Palace at the Magic Kingdom where you can meet Winnie The Pooh and friends. Also
Tusker House (for Donald's Safari breakfast) at Animal Kingdom, and
Hollywood & Vine, for Disney Junior Play 'n Dine at Hollywood Studios. Dining reservations can be made up to 180 days ahead of time,
online, or by calling (407) 939 3463.
If you have any more questions regarding 'things to do' whilst at the parks, or any other planning questions, please come back and ask me - I would be happy to help you plan your magical vacation!