Juneau--the glacier/tramway you can easily do on your own. I would especially recommend that for the Mt. Roberts Tramway part so you can decide that day based upon the weather. If it's foggy/rainy, you won't see much on the Tramway/from the top. Disney has a free shuttle bus that takes you from the port to the start of town--which is right where the Tramway is. At the location where the shuttle drops you off there are also lots of tour companies. We were only planning to do the glacier and some shopping after--so we booked the Glacier Express shuttle bus through Juneautours in advance through their website--but we could have just bought it that day. In 2016, it was $30/person roundtrip--the buses left every 1/2 hr on the hour--so you could take any bus back that you wanted if there was room on it--just be mindful of the times so that you get back to the ship early enough. (The bus picked us up in the same area that the Disney shuttle left us in town.)
As far as the Mendenhall Glacier--they do not allow you to bring any food or flavored beverages due to the bear population. At the Mendenhall Glacier Visitor Center we picked up junior ranger packets for our kids (Tongass National Forest)--which they worked on. We did the walk to Nugget Falls, toured through the visitor center, etc.
I can't comment on that Ketchikan excursion. We did the Disney 'Saxman Native Village and Lumberjack Show' one--which we enjoyed. The Lumberjack show is campy, but DD16 loved it. The Lumberjack show is actually in walking distance of the ship's berth in Ketchikan--so that's another thing that could easily be booked on your own. We did like the combo of things on our excursion--learn some stuff about the native Tlingit tribe/totem poles, and then the fun Lumberjack show--with free time in between which we used to just walk around Creek Street.
