Wow! That is a huge itinerary. Let's see if I have anything to add.San Francisco to Vegas
- agree with the rec to see Yosemite. I would call right now for reservations for this time next year. Curry Village is where I usually stay - it has a range of prices, from cabins to heated tents to (brrr) unheated tents. I would get 2 nights so you have a full day to explore.Vegas
- I am not strongly interested in most of the Vegas experience (although your Elvis wedding sounds fun!) but if I am there for some reason, one of the things I like is the Ethel M Chocolate Factory Tour. It's just a little outside of town, so if you don't have a car here, skip it. But if you do, I love the tour, the chocolate, and the garden - cool & peaceful! I also agree with the rec to see the Grand Canyon. Minneapolis
- I think it is a fine idea to stop here between Vegas and Boston. The Twin Cities have a plethora of things to do. Here are a few that I can think of: Fort Snelling (living history), Mill City Museum (excellent museum, plus they are always baking cookies or bread for treats!), Minnesota History Center, St. Paul Cathedral, Science Museum of Minnesota, Minnehaha Falls, Bell Museum of Natural History (excellent dioramas), oh I know there is more, oh yes, St. Anthony Falls plus the surrounding historic district and the Lock. That's enough to be going on with!Florida
- specifically around Mouse Country (so I won't mention St. Augustine
) I recommend a swim in a springs, like Wekiwa Springs - I love the water, warm and soft. You can also rent a canoe for a couple of hours at most of the springs - they're everywhere! Blue Springs State Park is good for seeing manatees, but the season starts mid-November, so not sure if you'll see any - you might be a little early. Blue Springs is better for manatee viewing, Wekiwa Springs is better for swimming and canoeing, but there are springs all over Florida. Also fun is Gatorland in Kissimmee, an alligator theme park (for something just a little different!)Hawaii
- it is definitely not too cold to swim in Hawaii any time of year. Although the waves do get bigger as winter comes on, but there are plenty of protected places to swim. Recommendations would depend on what island - will you be likely to stay on Oahu? Perhaps go to the Big Island to see some volcano activity?
It sounds like a fun trip, and very ambitious - I hope you and your DH have a fun time, whatever you choose!