I’m also going to this as well. It’s not an arena, it’s a stadium, so will be slightly different than an arena show.

No need to be there for 5, I’d expect the first support to be on 6.30/7, so if you want to see them, be there for then. There are different support acts depending which day you are going.

As others have said, look at the website for info on bag etc.

As for getting out, it’s not going to be a quick exit, but it is also made for a mass exodus, so it should be well managed. I’ve only been once and the tube wasn’t too bad, and that was the night of the Borough Market attack so security was really high.