Yeah, if all you are doing is HPDE's, then the confidence inspiring setup is fine. You're not really allowed to time anyway. *shrug* If you are using HPDE's to prepare for something bigger, then you still may want to start experimenting outside your comfort zone. In fact, you need to work on driving the wrong lines a good bit rather than just the right ones. Nobody is going to let you pass on the good line. You're not going to be able to keep the good line when someone is trying to pass you, either. That's where the good car control comes in, too...when you're not where you intended to be but still need to find a way to make it work.
You might think the most likely time for you to have spins and offs in road racing is due to "activity" in the corners (passing and getting passed). In my experience, that hasn't been true. Sure, I've had plenty of contact in corners with cars, but 90% of my spins or offs have been self induced with nobody around me. Basically a result of just trying to push too hard to get faster lap times and running out of talent.
I'm not sure how many people saw me in the Portland MX-5 Cup race on TV, but they had a shot where Laura Olsen punted me and passed me. My car was a push monster that day, but if I even tried to toss it around to loosen it up, it just seemed to go too far. I saw her coming and as she was *about* to hit me, I started to countersteer for it. She hit me, I had the counter going, and while she did get by, I really didn't lose that much momentum. I had overdriven my front tires trying to stay in front and just couldn't get the thing to turn. I realized that after she went by, so I took it easier. She probably overdrove hers and a few laps later I went back by her in the same spot with a light tap. She didn't go around, either.
I probably couldn't have stayed on the track if that had happened a year ago, but you get a lot of experience being shoved around in MX-5 Cup.

The more off line driving experience you have when that happens, the better. Being able to see the marbles and how bad they are in an instant becomes important, but so does knowing what they are going to feel like. Use even those HDPEs to see...you can explore out there fairly safely if you take your time with it. You probably shouldn't do that until you graduate to a no-instructor class, though. Don't want to be giving anyone any heart attacks.
--Donnie