Hi there. Don't post very much in forums, but this topic caught my eye, since I spent a lot of time wondering those things too.
The pedal Edge uses is not a wah, but an expression pedal, which can be used to control different effects, wah among them. For Elevation and Even Better Than The Real Thing intros, Edge uses the pedal in order to increse the pitch of the notes he plays.
Now, for the guy who asked for Edge mistakes at Vertigo tour, I remember watching a boot video from San Diego, second night, but I just can't find it. When they start playing 40, Bono stops the song and points both Edge and Adam are playing in different keys. They laugh, because that's a childish mistake every bass player in the world gets everytime (Edge is playing bass).
But mi favorite video to remember Edge is human, is Amnesty LA '86. They can't start the song because he can't get into the intro riff! Notice Larry's and Bono's impatience. And the solo during Pride is just awful, nothing to do with his usual skill:
Edit: sorry, don't know how to post embbed videos, I'm more the twitter kind of guy.