With regards to the open pit lane, the track we go to has sessions in the morning, then runs an open pit lane in the afternoon.
The track time session for each group of 12 cars out, lasts 15 mins usually. Then you come back in and line up again if you want, or dont.
Maybe they do it differently here, but I thought open pit lane means you dont have to wait for your allocated session, its first come first out.
It would not be right to not have a timed session, people would be waiting to long sometimes.