I never tried getting all golds in the liencense tests in any of the GT games.  Also in order to do it with a controller you have to be extremly good in the game.

I think I'm bad, but I dedicated enough time to pick the golds on basically all the GTs. But Sebastian Vettel is just impossible for me on the controler.

I'm terrible at all those challenges the only one I completed was the AMG Driving Academy which is kinda surprising since the full version of the Ring is actually one of my least favorite tracks in any racing game that has it.  I will probably go back and get the trophy for Gran Turismo Rally its doeable since you can choose your car.  Came really close to finishing the Top Gear Test Track special event but I just can't handle the Lotus you have to use in the second event. 

I like the idea of having my games on an external hard drive to take to different rooms or peoples houses.

getting gold on full nurburgring is a dreadfull feeling. I always love Rallies. The lotus problem is that you can't full throttle, try to go slow and controlled and them slowly raise speed.