Hi, lets see if I can answer a few for you -
1. Yes.
2. It was my first time last year and I didn't see anything. Food is plentiful as there are loads of stalls. Beer etc - there are cider buses (you must try the Brothers Cider at the West Holts stage

) and plenty of beer tents. If you want a specfic beer or whisky you'll have to take your own.
3. yes there are secure, 24/7 places you can leave your tickets , bags etc.. No charge but they do ask for a donation (they are set up by a charity).
4. - sorry don't know. We go in a campervan.
5. No, once your in the arena it's all open to you. Only those in the campervan fields have to go through security evey time the enter/leave.
6. Yes there are some breakers, but only at the Pyramid stage. Not as many as at rock am ring. The crowds do get big at the pyramid stage but not as "crazy" as a full on rock crowd!
7. erm sorry don't know.
8. depends on who is on at the other stages and if they get a big draw. EG last year Nick Cave was on before Blur - it was fairly quiet for Cave, about half way through it started to get busy as people turned up for Blur. Maybe someone with more Glato experience can answer this better

9. Moving between stages can take a while, the only tip I would give is don't try and get from one stage to another to see bands that are back to back on different stages. You might get caught up in a crowd and miss the band. I found getting away from the Pyramid and West Holts took a while last year, the rest not as long. Also depends where you are stood.
Hope you enjoy Glasto - I loved it last year and am so excited about this year!!