Join Date: Sep 2001
Location: Florida with my baguette
The first year I went I was tentless, so it isn't necessary. But then I have also been grateful to be under cover when the rain came at one time. If the weather looks like holding up, you'll be fine.
As for what you need, you've pretty much got it sorted with your list. One thing I'd add is a stool or some collapseable seat-thing. There's a lot of waiting in line so unless you don't mind standing or sitting on the ground and risking piles, then take something to sit on. It isn't so important, but it's something I'm glad I have.
I went to the museum in March of this year and there were no toilets, so I think they are a temporary measure put up for the fortnight of the Championships. As far as I am aware though, there are toilets which make do as washing facilities.
Something to pass the time might be good. And as mentioned earlier, there are left luggage places where you can store your stuff during the day.