Oh, and I agree about the Billy Fluffs. Not only did he not stumble that much, not all of it was him forgetting the lines; some of it was characterisation!

Especially in they "They've all gone" speech, where someone's yelling "cut!" in the background as he says "Chatterton". I'm 99% sure that was in the script! (Of course, since we have a team who don't even know how to switch the central column on, it's possible they don't realise that...)