Iggy is a bit of a tick off.
I think Underworld and Girl in Red is all from that list and I'd expect Underworld to heavily clash with Green Day anyway. Beth Gibbons definitely not for me. Elbow I've always thought are one of the most boring and dull acts around and live didn't change that. But that's all opinions.
No it's in the day. I've had a couple of moments, Glastonbury 23 I rested through RB for Arctics as the heat just took it's toll and i was working that year realising how much it takes it's out of you being there a week earlier and doing your shifts. Obviously getting earlies was the great full part. 2010 was difficult at moments. Strangely, I never really had heat issues watching bands at Coachella when I went and that's wall to wall dessert heat.
I think Linkin Park were out for a while. If the festival had them I can't see them having not announced them for sales.