I only made 2 concerts in England yet so I can't say very much. The Hyde Park Venue is huge so if you want to get to the front you must be there really early I guess.

Because of photo cameras,it varies. Most of the times small cameras without a zoom are okay.

Take enough water with you but in plastic bottles or tetra-packs, not in cans or glass bottles because these are forbidden. In Wembley and Shepherd's Bush we could take water in plastic bottles with us, they only took away the closure for some strange reasons that I don't know. I never heard that food is forbidden.

Sorry, this probably doesn't help very much but as I said I was in London last year for the first time for a concert.