hey, I go there!!! Here's your answers
1. Most people use the last 3 numbers of their MRA membership. You can use any numbers you want, though. My friend is always an electrical tape 111. If that's taken that day he's 777 or 111x.
2. Those are the fees and the membership is only good at milan or delta
3. There are 3 classes. I know there is one that includes 85s.
4. Here's how to register. See the lady at the gate and give her your money for racing. Park in the pits (as far away from the bathroom as possible at Milan). Walk to sign up and pay for the membership, as well as fill out paperwork for racing. That's it. The tracks are small and it is super easy to register.
I guess Delta was a national track back in the day. Now it's still fun but NOWHERE near a national caliber track. All AMA tracks in the area are nicer. Milan sucks. I used to race there every week until I discovered how much better every other track in the area is. I made my wife promise me that she will never let me go there again, even though it is 20 minutes from my house. They are also more expensive than most other tracks. Hey it's my second post ever!!!!!