(1) There's are all sorts of different ways to go in this course, but only one will get you through it the fastest. That path is left, right and left. The second best choice would be to take the path, left, across the narrow ledge, past the item boxes, and right. I recommend the second choice over the first because of the many porcupines on the first. All the other ways are a lot easier than these, but they won't get you through it at nearly the same time.
(2) This can be a handy shortcut if you have a turbo or a super star. Just simply use a turbo or star to cut across the grass to the finish line.
(3) SUPER SHORTCUT!! Right before the big turn, where your track meets with the one on the other side, jump across to the other track so that you can avoid the bothersome trip of going all the way around. Once in the air, hit the brakes so that you can avoid bouncing off that track and going off the cliff. You should shave off a few goo seconds.