Happy Birthday, Moptopper (etc) - good on the wife for 'breaking the rules'.
What a bunch of tossers - how stupid, why wouldn't you want 'a personal message'? Authors do it everywhere, it's part of the gig - you don't crowd manage a book signing (of all things). If it was me I'd have a ball with it - I'd write stuff like 'Sylvia really was a donut', 'E-Girls Suck'; 'Eyebrows was a w#nker', 'Phil Read deserved it', 'I miss the anchors' (and stuff like that)...Pav has a great sense of humour, no doubt he would have some fun with it.