If you can get a one way rental car, check out Kenai Riverdog. We had a fantastic time with her on the river last summer. I would recommend keeping a change of clothes/shoes handy just in case you get a little wet.
Since you mention glacier there are a couple options near Seward/on way to Anchorage. One option is Exit Glacier in Kenai Fjords National Park. The hike wasn't too difficult and it was interesting to see how the glacier had receded/changed over the years. View of the glacier was further away. Another option on your way to Anchorage is the Byron Glacier Trail. It was an easy hike to a glacier that you can actually touch.