With regard to the mosh, just be in the first 3000 or so to get there and you should get a wrist band which allows you to pass in and out of the front area in the knowledge you will be only so far from the stage at worst.

Uh, with regard to the signing, don't bother bringing an album, apparently the organisers have it set up so that you have to buy one from there to get it signed. It sucks, but that's the way it is I guess.