Good list.
Something we do is rent one of the lockers on Main Street. Largest locker is $10 for all day and is worth it to store water, food, jackets, and a blanket to sit on for the fireworks show. It's only a short hike from anywhere in the park, and saves my back from having to carry it all day.
That's a BIG 10-4, Zen. We saw a lot of people going into an innocuous looking little building and decided to check it out. It was the locker building you mentioned, and scads of people were making good use of it as you suggested. VERY good point.