Guys, it's pretty bad form to just say "that opponent sucked" when some one asks for advice.
Shiz, one of the things I would say to work on is some of the ledge game: you had one great ledge hop d-air for the kill, but other times you should have taken a stock off but didn't. At (:29), I would have gone for a spaced n-air ledge hop to throw Sheik back off the stage (since she was at moderate/high percentage). That or a quick ledge hop-> waveland to fsmash to get her off (instead of an u-air to try and juggle her at high %'s). Also, at (1:30), you kind of hesitated in getting down on the edge when Sheik was under the stage and then got down too late which resulted in the loss of a stock.
Also, some shffld nairs were a little poorly spaced and could have been shieldgrabbed by a more observant Sheik.
Still, you have a very good Marth