Just finished achieving gold trophies in MK8 last night on all classes, including 200cc. 200cc was quite challenging, and I had to redo a few of the cups many times. The ones I had the most amount of trouble with were the Special Cup, the Egg Cup [first cup in first DLC], and the Bell Cup [second cup in second DLC].
The Special Cup challenge was Rainbow Road. Rainbow Road wasn't bad once I figured out a decent way of doing it, and I had never done that mid jump shortcut after the boost bumper thing [great description I know] but once I did that, along with pacing myself and not rushing too much, I had very little problem. Before that, I was falling off the edge constantly. The encouraging thing is that even the CPU's seem to fall off the track in many sections too.
The Egg and Bell cups were insane on their own as a whole, and I think a lot of this is because these courses, with the exception the Excitebike one, are really small for 200cc with lots of quick turns. These cups both took multiple tries to get gold, and I found myself constantly hitting walls on turns. I ended up easing off on the gas while trying to still drift for a lot of them, and some turns were so tight at that speed that I had to drift/hop more than once on a single turn to get a sharper turn. I didn't end up using brakes at all for any of the cups. Only a mix of easing up on gas and drifting, and knowing when not to rush myself and take shortcuts. It sounds stupid "not to rush myself" on 200cc, when everything is rushed, but it's true. There's some sections where just taking your time around a turn and not hugging the walls [making you go much slower] can make all the difference and keep your place.