OP Great Post. I was on that fence and was easily swayed to try tracking my car this summer. I have yet to register for some local events, but I have started to find a decent approved helmet, but didn't consider the points you have provided; although obvious to some; I was going to overlook a couple things like "brake/oil fluids" ;
I havent searched the forums. but this is a good sticky for those on the fence.. and need to know the basics to maximize their investment.
Subscribed and found some DYI linked to
http://www.m3post.com/forums/showthread.php?t=333653