Okay, so I watched your set with Dandizzle who, ingeniously CP'd to WW, lol.
Overall, you're not half bad. I definitely see a lot of room for improvements. For example, I see that you were occasionally spacing Fairs in the neutral. Sure Fair has great range, but it also has a lot of end lag, and any good DD character is going to weave right past it and punish. Also, going off stage is very character based. You usually don't need to jump off fair Sheik, because you can punish her UpB landing lag by doing a standing get up and then just charge dsmash, grab, utilt, w/e you want.
Things to work on IMO would be spacing more with ftilts/dtilts and making sure you always keep waddles around (you seemed to do that), as they help in a ton of situations. D3 also has a great RAR with his fair, and a great nair OoS, so it would definitely be good to incorporate those. You went for a lot of shield grabs when you were obviously being crossed up which ended up with you getting punished. A nair OoS would typically cover this.
Just overall neutral game, and solidifying your punishes. Nothing was bad, just sometimes sub-optimal.
Edit: As a player, you're not bad. I think you're outside the range of top 10 LI, but not TOO far out, maybe close to top 20.