First, we commonly call Lego animations "Brickfilms" or at least "Lego animations," "Stop-motion" really isn't a great way to describe them, because that could also describe a claymation video, or even the special effects of an old Godzilla movie. And you should have changed the title of the movie of the video on YT to "Revenge" because "Lego movie" could also describe a number of things.
As the the video itself, there was some prop, set and camera bumping, but you've already noticed that.
You need to ease-in and ease-out of your motions, (See here) your frame-rate is fine, just the movements aren't realistic. And when the robbers are killed, (0:54) they should have fallen backwards off of the building, or fallen forward onto the wall, hanging down like that is against the laws of physics. Walking up the side of the wall (1:08) is also very difficult in real life, the guy should have climbed up it, or at least leaned really far forward after running really fast at the wall. Your sets could also use some work, but that all hinges on the amount of Lego that you own.
Plot-wise, it had some problems.
Spoiler (click to read)
First, if the feller is capable of taking down an entire band of robbers, why couldn't he have kept his wife from being taken in the first place? Second, why would the king instantly allow him in the throne room? And who ever takes the word of a robber, and then turns around and blames the king for it? The ending was a let-down, after all of that, we don't even get a shot of his wife in the prison of the king. A (Slightly) better ending would have had the king taunting the wife with the news of his death and her screaming in agony.
So in conclusion, the plot could use a lot of work, and you need to ease-in/ease-out, but overall it wasn't too bad.