Haha, that looks an awful lot like my Marth.
If I have any suggestions..
Try not to up-b as much as you do, it's a pretty chance move that only works on occassion and if you set it up perfectly, not good for standard use. Practice wavedashing a bit, practice grabs, short-hops, l-cancelling, all that jazz.
If you want to practice wavedashing and short-hops, do what I do. Try short-hop Nair, l-cancel, and then right after that, wavedash backwards or forwards (Assuming you already know wavedashing), and try doing that until you get it in one fluent movement. I find that helps for practice.
And of course, practice your *** off, man. No one got really, really good by just playing on and off, you need to put much effort into it if you wanna be good.