I managed to gold all the licenses with a DS3 (Using only ABS in Auto) before the controller sensitivity option was introduced (which I still see no need for tbh) (I recently did a few events with the wheel and I did manage a few faster times!)
Like has been said there is some need for repetition, but I think licenses such as Indy with that Nissan & the FR Slalom with that Lexus where probably the harder ones.
On some tests I found you just need to barge your way through, such as that one at the end of Tokyo in those slow hybrids, just push the Prius out the way lol!
Golding the licenses is a good thing to achieve as they force you to try new lines, which can help in overtaking manouvers etc. in online racing, things like the Pug at Tsukuba, the Integra at Autumn Ring & the Swift at Deep Forest. The S-License is very useful aswell I feel, as if you hit the other cars you will be disqualified, but like in online racing you have no idea what others are going to do next, so that helps you learn where you can position your car etc. (I know they can hit you and you can get DQ'd which I know is frustrating but you'll get past it!

)
Only thing about the licenses is the addition of that restart confirmation box, I bet that'll wind a few people up whom are going for golds.
Oh also, aswell as the licenses, go and gold Special Event Grand Tour at Eiger, that'll teach you to take new lines aswell!