Tiger,
Did the previous owner give you the original sway bars? If so, reinstall them.
Regardless of what shocks/springs you're running, these will put you back into a 'normal' range (with a bit of understeer if you have stock suspension, but that's fine when you're still working on the fundamentals).
From what you have posted, IMO, you now have a confidence problem after looping your car twice (which is completely reasonable from anyone spinning a few times when they first start out!). Until you get your confidence back, your learning curve will flatten out because you will be afraid of everything and will be paying too much attention to the wrong thing (my car is twitchy/understeer what can i change/tune to fix this).
There is a reason it's a common recommendation for people to start their track schools/days with close to stock cars. Alot of the blingy performance parts you read about on the net, magazines and these forums *might* be well and dandy, but you won't have the skills to fully utilize a stock car (specially an nsx!) let alone a modified one. And if you can't get close to fully utilizing what you have, there is *NO WAY* you will be able to set it up. Please don't take it personal, it's just the way it is.
If you want to get the most out of your track time and the instructors time, get your suspension back as close to stock as you can and do a few more track days. Let the instructor know about your last few events and that you looped it a few times (it isn't anything to be ashamed of). Only focus on your technique and line for the next couple track days (not just sessions, i'm talking about all your track time).
After a couple track days like that (it's different for everyone, could be just one event or it could be a dozen, take your time) you will have your confidence back and will have *substantially* increased your skill. Your laptimes will be *way* lower and you won't even have realized it.... then the go-fast crack pipe really kicks in, and you can start changing your setup... 
Cheers,
-mike
