You can park on post.

Main post on the right, no need to place the coursemarshals too far away. If there is a crash, it is a big one and you will never know where they end up.
More of a flag post.

Nothing!!!!!!!!!!!!!!!!!

In normal circomstances it is a boring post, the straight is far too long and uphill and those drivers will park far away anyhow.
Be prepared to do lots of running.
If something happens, it is big. As a marshal you have to stay alert because of the high speeds. Very often there are multiple car crashes, usually with some rolls.