Best way to combine Vegas and Canyon
To my mind, the Grand Canyon trumps everything on your list. And the best way to see it is to either hike along the North or South rim. When you go to the Canyon from Las Vegas, the trip will take you to the part of the Canyon that's controlled by a native American tribe and unfortunately, there's not as much hiking allowed and part of the canyon has been defaced with a large glass walkway. If I were you, I'd consider flying into Phoenix and driving from there to the canyon, so you can spend a few days enjoying it and the surrounding area. From there you could fly to San Francisco (though that could be pricey). I hope this helps!