Not sure how much I can add but...
First of all, the SOB's got me hooked in April of 2006, so I know how you feel. While a bit odd, these folks are mostly harmless, and a lot of fun.
About the 'cage - all I know is my own experience with my Mustang convert, which was built for NHRA brackets. First if all, T-tops are considered, for ECTA safety purposes, the same as a convert. Second, my 'Stang has a Maximum Motorsports 6 point, and is tech'd by Keith at 150. I couldn't have run at all without the cage. I have a rear-mount battery w/outside cutoff, and again, this was necessary. As far as 10 point vs 12 or 14 points, and higher speeds, I'd E-mail Keith - he da man.
If you want to do some volunteering at the track, contact me and we'll find you a job. When it comes to volunteering, I be da man! (But just recently). You can get me thru the website, or at email@example.com
Welcome to the party!