This is a lot of good advise. I have done 5 track days on a motorcycle before, but never tried autocross.

Is autocross courses generally tight slow corners? Does speed ever exceed 60mph?

I find the evo handles very crapy under low speeds condition(5-10mph) due to the poor turning radius.

 

Yes, the courses are usually tight and speeds usually stay below 60, but an Evo will still be fine. I had the same concern when I first started autocrossing in a 2G DSM, which also has a large turning radius, but that was fine, too. Just don't dive into the corners too fast - slow in and fast out - and the car won't push (understeer) as much.