This is a very "on the go" itinerary. I suppose you only have the Natural History tour??? Or lucky enough for the Tundra Wilderness??? Hopefully you have the former, otherwise, make some good choices for wildlife elsewhere, you likely won't see any in Denali Park.
Flightseeing is the forte in Talkeetna, RCI also stays at the beautiful Talkeetna Alaska Lodge, a great location.
Make the most of your time in Seward and don't be in a rush to get on your ship. Exit Glacier will give you very close viewing, Seavey's Sled dog kennel is great if of interest, The Sealife Center, is also very worthwhile.
You do not have a lot of time since a great deal of this trip is in transit. Make the most of it.