Hey dude I'm gonna give you a critique if that's OK.
First of all, GG's.
Now, to your gameplay.
I think you are pretty good. You have a lot to learn though. You had a few blaringly obvious flaws in your game. The first was tour excessive use of Dash Attack. Marth's DA sucks sweaty nuts, don't use it. Dashing in general isn't a good idea, walking is better, or running, but don't Dash. You seemed to Dash Grab a lot too. Marth's DG is bad, and if you want to do a grab out of a dash, do a Dash->Shield->Grab, it's wayy better. You Dair'ed too much in general, and you DEFINITELY Dair'ed too much onstage, a place where Dair shouldn't be used. You are also quite predictable, and I could predict what you were going to do most of the time. The Shield-Breaker recovery needs to stop. It isn't good, and more often than no, you would go under the stage while using it, and then you'd die. You need more Ftilt and Dtil, too, I didn't really see any of Ftilt, and only a little Dtilt. The down variation on the last hit of Dancing Blade isn't good, especially against Marth. You also don't airdodge enough, making you quite easy to gimp. You need to Up-B out of Shield sometimes too, it's amazing. And don't use Dsmash that much, it is easily punishable. Don't Counter as much either, that is too easy for me to punish as well. To get better, I suggest just lurking on the Marth Boards for a while to pick up strategies.
Now on to the good things. You are a good gimper. In one of the last matches, on Smashville, you gimped me amazingly, it was crazy good. You are a great juggler, too, and you used Utilt and Uair quite well on the ledge. There were more things here (don't worry) but mymemory is failing me now, I'll add on as I remember things, so re-check this.