When I see I am most likely going to have to stop up ahead, I shift into nuetral straight away. Sometimes while im still traveling at speed, is this bad? I don't think it is but just to be sure.
Honesty I think you should wait till you're 21 at the very least. Firsty insurance if you can get it at all will be hugely expensive. If you're interesterd in buying a fast car then surely you plan to drive it how it is meant to be driven at some stage and it's important to have enough expirience or you'll end up putting your pride and joy into a wall/tree. I think you'll fined most people will agree with what i've said.
I dont own nor have I ever driven a GTR but I've been a big fan for several years and intend to buy an r32 gtr next year. The 32 and 33 are very similar performance wise. Obviously the 32 is a fair bit cheaper than the 33 being an older model. I'd go with the 32 and with the cash you save do some mods if you want more power and possibly an engine rebuild as a precautionary measure. As I said I have no hands on expirience with either so my opinion might not be worth much.
I agree with BlackRobin importing is definately the way to go. Prestige Motorsport (import agents) are highly regarded. However under new law any modifications to a car must be removed and the car returned to stock before compliancing. Personally I prefer to make modifications myself so it suits me fine. Goodluck.