In regard to moonwalking, I found that I wasn't rotating the stick back up far enough after the semi-circle. Everytime I want a really long moonwalk I need to think hard about making sure I tilt the stick to about 10 o' clock. You won't jump, but you will have more momentum.
Another good thing to practice with moonwalking is that you time your jumps correctly. It's most reliable utility is when you're trying to edge hog. Get used to: dashing towards the edge > DDing back > moonwalk > short-hop/full-hop > fast fall > ledgegrab. With practice and momentum you can do it from anywhere on Yoshi's Story and 2/3rd's of FD.