Yes, you queue up to have a go and then off you go when you get to the front Theres only one car on each bit at one time (either the high speed bend for the morning, or one of the 2 courses in the afternoon)
TBH, I dont know much about the Bridgestones, but that sounds like a tracking problem. I had my NSF tyre start doing this before I had my tyres changed for Wales and that was defiantely tracking as the other one was fine. Its also a common issues with certain Bridgestones that the tyres feather (try doing a search on here for "tyre feathering"). I didnt think that issue was sorted a long time ago though.
As most people quickly learn, if you hoon around a track or airfield too quickly you will shred your tyres. What you need to do is go around near the limit but not over it. When you go over the limit and loose traction, that is when you shred the tyres. Ask Ben about his first track day at Bedford and his tyres If you control the car properly, you shouldnt get much wear. Plus we pump them up so hard, you break traction a lot early which slows the wear down.