Since you have a 2 year old, I would skip Fantasmic this time around. Might be scary for him and requires him to stay up later than you might want. My 2 and 3 year olds loved Spectro and Wishes.
We did AK from park opening till about 2 and felt we covered it. The parade is cute but I wouldn't hang out just for it - it's over in 10 minutes. We have done both parks in one day - one in the morning, then a break, then other other later in the day. Or you can do each park in the morning/early afternoon and then swim and either go back to the same parks at dinner time or evening to see what you missed earlier.
I could spend a full day in Epcot and obviously MK. I love both MK parades as do my kids. Depending on when you go and how late the park is open, you could go to MK early and then take a break and go back for the parade and dinner, or stay until the parade, then take a break and come back in the evening. At Epcot my DH and I just love to wander around the World Showcase, doing multiple loops, plus take time in Future World. I haven't seen Illuminations yet because my kids are in bed before it starts, but it's on my list for the next trip when they're older.
A park hopper pass is a must for us so we have the flexibility of doing a nighttime show in one park if we went to another park during the day. We always try to do each park once before we get to the end of the trip so that the last park day is picked based on what we missed and where we want to spend the last day.