The r35 gearbox is a good thing true. It's a big part of what makes the car quick, yet is the achilies heal in some respects. You're not going to see any GTR win a 12 hour i reckon.... Launch control, meh, is far from perfect believe me (rather moody) and makes no difference on the nurburgring obviously. Dashboard stuff is curious/interesting yet a waste of time really; will not make you 1/100th quicker on the circuit. If you have time to look at that stuff you're not going quick enough. Fuel/timing etc are just a given, no great magic there really, dial in the optimal mix and it's a done deal. Important to get it right but not space shuttle stuff.
The R35 is primarily quick due to:
1. Tyres/grip (you can get decent sized rubber under there)
2. Gearbox (instant cog swaps, mid corner without upsetting balance)
3. Great balance/handling for an OEM package
4. Power - gobs of!
ESP is just going to slow you down. At least the factory calibration will anyway..