1. Not sure. Current count is about 40.
2. Not sure what you are asking hear, but the day is planned to be a fun relaxing day for the entrants, with no pressure to become competitive.
3. You wouldn't ask such a question if you had ever run an event as big as this. Venue hire, insurance, flyers, club notifications, time tables, bbq, drinks, track layout, etc....
4. Car with a full tank of fuel, money for accomodation, food, etc., and whatever else you take on a cruise.