Personally i feel you have severely underestimated times for everything.
>>Day 1: Drive from Anchorage to Seward in the morning and spend the day in Seward kayaking, canoing, glacier hiking (Exit Glacier + Harding Ice Field) + Portage Lake + open to any other suggestions.
Drive back to Anchorage at night.
So you drive to Seward, takes 2-3 hours minimum. Depart 6am arrive by 9am. Harding Icefield Trail takes 6 hours or more. How can you even have much time to go kayaking and get to Portage Lake (for the glacier tour?). You probably miss one of the best things in Seward, which is the Kenai Fjords NP boat tour of 6 hours or more.
>>Day 2: Drive from Anchorage early morning to Denali National Park and get there around 9-10am. Spend the day at the park and drive off at night to Fairbanks. (or should we spend a night at Denali?)
In order to arrive at Denali at 9am you need to leave by 4am if not earlier. Then you get a 10am shuttle bus to Eielson and don't get back to the entrance until 6pm - and that is if you never get off your original bus to do any hiking. If you have dinner near Denali you won't get out of Denali until at least 8pm if not later.
>>Day 3: Drive from Fairbanks to Tok - spending the day at various state parks (Tanana). Spend the night at Tok.
>>Day 4: Drive from Tok to Anchorage - via. Matanuska Glacier
You are trying to keep your cost to a minimum but you are spending all this money on gas just to see the road system in Alaska. You are not doing anything between Denali and Matanuska Glacier (and even then I assume you are just going to "see" the glacier from the road). That is a pity.
I would suggest you skip Fairbanks, Tok, etc. Return from Denali to Matanuska Glacier, take a glacier hike (that is the real highlight of Matanuska Glacier). On the way you can see the Veteran's Memorial at mile 147 of the Parks Highway, go to the Iditarod HQ in Wasilla to see the film and even take a short dogsled ride, go to Independence Mine area, the muskox farm and/or reindeer farm. All are very inexpensive or free. And spend an extra night in Seward so you can really see it.
Do you fly out of ANC the evening of Day 4? What time?