I was nursing a sore foot, so I knew that if I wanted to really maximize my time in WWHOP, I had to do that exclusively, and not stop too long anywhere else. So, I probably spent about 5 hours in Diagon Alley the first day, and about the same amount of time in Diagon Alley, and Hogsmeade the 2nd day. Remember, now I go slower than most folks. I am 69 years old, and my gait is definitely that of a hobbler, not a normal walker. I don't normally ride thrill rides, so I wasn't there for the "top mentioned rides". However, being a huge fan, I saw so much that reminded me of scenes/stories/characters/moments in the books and the movies. It's easy to rush through the place. You really do need to slow down, just to get the full measure of enjoyment. The reason for spending less time in Hogsmeade, was because I was there before in 2012.
I like doing these sorts of things solo, because I love to take photos. Other people traveling with me, would most likely be bored, because I stop so much. However, I tell people ahead of time, about this, and they gladly go off on their own.
I wish you a wonderful time. Definitely ride the train both ways. Not necessarily in the same day, which is what I did twice. However, the video on the train in the compartments is different each way. Definitely a must do/see.