WOAH, within 12 hours and you've got everything sorted.
I'm like you at start. I didnt know about all these defectable items until I BOUGHT the car and start talking to people and asking questions (didnt even know carbon bonnet is defectable, but they dont really get you for that). Anyway Dont do stupid things and have any attention seeking mods, and you'll be fine. I've been pulled over once since I bought the car (bought in March this year) and thats just a normal rbt check (wrong place wrong time, thats what I think). Saw my ring with my wife and they didnt bother with me. Have fun with your GTR in a sensible way and you'll be very happy that you did buy her!