Yep, my rear tire pressures after the first 20 minute session were 45 psi. Reduced it to 37 psi immediately before the 2nd session but both instances of oversteer in my video still happened about 10 minutes into the session.
I don't have the rear beam bushings. My car is totally stock at the moment. Once I decide to take the plunge with handling mods I'm going to pick Jeff's brain. His Stoptech BBK was definitely my favorite part of his car as well.
Dunlop Direzza ZII Star Spec comes in 215/40/17 and 265/35/18 on Tirerack.
I agree with most of the comments given so far. 45psi is bit too high, and if you waited 30 mins or so between sessions to drop the pressure to 37psi just before your next session, it's likely your pressures were still too high. As others have said, you need to check your pressures immediately after coming off the track, preferably with little to no cooldown.
Are you on stock 205/225 width tires?
I'm not a huge fan of HP+ pads, I would go with something a bit better.
Overall your driving looked pretty good. The NSX is a well balanced chassis and does what you tell it to. Heavy trailbraking is good to rotate the car, and it actually does, but if you didn't want that entering thre corkscrew, you need to back up your braking point to not trailbraking (and rotate) as much when turning in to the corner.
I would hardly call your moments "big snaps", you didn't let them get that far out of whack and caught the slides fairly early. Your big OS moment in T11 was from trailbraking, unloading the rear, upsetting the car over the curb, then aggressively getting on throttle. Keep in mind if you do get oversteer, DONT punch the throttle. That's a really bad habit to get into. As skip barber teaches: "When in doubt, both feet out". As others have said, keep learning the car. Most of the issues are self induced.
The standard size is a 215/265 on a 17x7.5 and 18x9.5 personally I'd go with a 17x8 and 18x10 and use a 275 rear tire.
+1 on seriously considering a baffled oil pan sooner than later.
I'm a bit surprised you were having heating issues with stock power. Not sure if your radiator is just old and clogged, or if the radiator fins are all smashed in to reduce its cooling ability.