Risk of bear attack is really quite small provided you follow the sensible guidelines for food and garbage storage. People have been camping in Yellowstone and Alaska for many years with a relatively small number of incidents, many of which might have been prevented by not keeping food, or other strong smelling items like toothpaste that arouse bear curiousity, in the tent.

Only destination on your list I've not been to is Hawaii. Can't imagine it being possible to make a bad choice from your list. All of the destinations are ones I keep returning to over and over. While there are roads going through Yellowstone and Alaska you will find that there is far more to be seen by hiking, canoeing, rafting, dog sledding, small boat coastal cruising for coastal states and BC as well, and any other means of getting around that you can think of. Assuming it is to be a family type of adventure, I would advise finding something that everyone can be involved with as there is nothing worse than getting a couple of days into a week long hike and finding out that someone isn't too happy with it.