Hey how are things?

I have just listened to 'Promenade' and thought woo its actually a good song, but I see it has never been perormed live, why is this? sounds simply enough to play. Perhaps its a bit quiet and not enough energy in it to make it to a live set list.
What other songs off their albums have never been performed live? (to me 'when i look at the world' was played live even though it was a snippet and sung to the music of bad)
Does u2start have every u2 bootleg ever made, or are there a few out there that were recorded but are not uploaded?