I'm not so sure I'd be happy with "volatile" but I guess that depends on your definition.
Banter is great and chants/songs can be funny without being offensive - personally I cringe every time I hear the "land of your fathers" song, but that's just me I guess.
Also agree with the open coats thing - I remember dragging myself down there in January with a stinking cold, pissing down with rain ticket in one hand cup of coffee in the other and being asked to open my jacket - I'm a middle aged fat bloke and one look at me would tell you I'm not carrying anything offensive and if I were it would be in a pocket, if your going to check people for weapons, flares or horror of horrid a plastic bottle of pop with the lid on then at least check properly.
As someone else said, I'd love to see divers get a straight red and/or a long ban, but it's probably unfair to put that much pressure on a ref if he gets it wrong.