Alright, let's be honest: This submission still needs work.
First of all, let's talk about the draw, which left me a bit..."unsatisfied".
I'm not going to say your idea is bad (in actuality, it's good) but its execution is a average. The player takes out the knife and all of the sudden, this one starts spinning in mid air, and I'm saying this because the hand is barely touching it, and it'd be impossible for it to spin that much without falling.
Both of the arms act in a very robotic way, too. The right one, for example, just goes up without any rotation, or anything. Just goes up. Something similar is to be said about the left arm as well, which rotates but in a pretty robotic way.
You focused so much on the knife that you forgot about everything else.
Now, your light attack. I wouldn't really say there's a flaw on this animation, but the knife descends too much, almost as if it was being used like a long blade. Another thing that I noticed is that the animation ends too abruptly, with the hands (and weapon) suddenly stopping any movement.
The heavy attack pretty much ends all of the sudden, too.
You should notice that the default knife has animations that always end with light movements on the arms and weapon, thus making it look more natural. Try doing this next time.
First flaw I noticed is that the knife is always clipping through the fingers (the hand is always closed) on both stab and miss (in which, once again, the knife falls too much). The stab lacks force for a heavy attack as well. Since the arms are already animated to resemble force once the heavy stab happens, I'd recommend to make this effect stronger.
Other points to take is the fact that the skin has no animated idle, which is not a plus in my opinion.
I'll rate it with a 4, because aside from that, the skin has no player or world models.
To give you a reference of how animations should be done, take a look at IIopn's Eickhorn PRT VIII animations. I know it's on a different engine, but it's to give you an idea of how you can re-do animations and also knowing how to take out that robotic effect out of them.
Hopefully, this didn't offend you, and if it did, sorry, but I can't just rate something poorly without justifying it.
I'd recommend looking for well-rated skins on the site to take references from as well.