Our main options were to walk around the grounds of the memorial area (lots of plaques and such), a free historical museum and 15 minute video, a ticketed submarine museum, and the gift shop. We spent our full two hours reading the plaques, watching the short historical films and walking through the free museum and shop. If you visit and want to do everything, you could easily spend four hours in the memorial area.
Whoever we are and wherever we're from, I think we should visit our "hallowed grounds". No matter how much you hate war, don't avoid the concept of war. Immerse yourself in the atmosphere of the spots where it occurred and feel what you can feel. Americans should visit Gettysburg, visit 9/11 Ground Zero and visit Pearl Harbor. (There are other American locations, such as the Alamo, Wounded Knee, etc., I won't try to name them all, but I hope you get my point). You may hate it all, or be proud of it all, or feel lucky someone made sacrifices, etc., but at least you "did the research".
There were Japanese-American customers on the tour bus, and I wish I could have heard how they perceived it all. The tour guide was good, but he was a white guy about my age and did not seem to have an official script, so his "stream of consciousness" comments were from his perspective. The guide was not a park ranger or military person, "just" a commercial bus driver. The historical information at the site was mostly objective, and there was information about American internment camps. Today, the US and Japan are allies, but things were pretty brutal in the 1940s.