Yes as Kameleon stated all info is available on the website.
Q1: No, you can use a AASA license which can be purchased for $50 at the track on the morning or Sunday afternoon of the trackday. You can use a L2S CAMS license or higher if you have one.
Q2: Yes you need a helmet. You can use a full face bike helmet or hire one from the track. They have a few there.
Q3: Cost is $440 for the two days
Q4: This includes, 6 separate timed events on four different layouts. CAMS Hillclimb/Clubman Circuit/Tarmac stage/Full circuit.
Timed events include sessions on the mentioned tracks plus a hot lap shoot out and regularity. These are spread out over two days. Also, you have passenger and training sessions over the two days, a few cruise sessions for low speed experiences, on track photo shoot, use of garages instead of open garages at the rear of the pit straight, official weigh-in of your car, BBQ and drinks and one nights accommodation.
Thanks for the enquiry Eddie