Not sure on the first two, I'm not a ACO member so don't get no box. Green fence? Never made it that far (we have Martin to look after).
As for roaming the paddock, yeah, anytime you like. You can walk round at three in the morning on the Friday if you want to-we did four years ago and you would be surprised how many other people had the same idea. It's very laid back- we even watched the end of the final race from the pit wall that year!