Many people might come to Warsaw from abroad. There were so many people from Germany in Prague in 2003. I talked to two of them, and they said it was even cheaper to travel to a concert in Prague than not travel and go to a concert in Germany. And we have a great concert audience, I'm sorry but I guess Germans don't at least at Stones shows (usually older and quieter which makes a great difference from a noisy crowd).
Sorry to say that Sater but You are just being childish with Your anti-Warsaw aproach. People are not different in Warsaw.
I can see from the concert map that there should be plenty of entrances to the concert site so no reason to worry about what happened at the U2 show in 1997. Anyway even if it was in Chorzow the organiser would be the same so what's the difference?
I am kind of interested in going to Bergen for the concert. It is expensive but what the hell? Only shows in Eastern Europe will be cheaper, at least we have cheap flights from Gdansk to Oslo. Might want to go to Holland as well, depending on ticket and flight prices. Vienna and Brno also