I'm p sure I had seen some of those before. I'm not too much into skateboarding so I'm not too sure on what's right and what's not but the stick's center of gravity seems off while he's just standing on the skateboard. Also remember that you need to exaggerate movements a little in order to make everything that's happening clear.
The doors animation is alright, some poses feel weird. Mainly when he takes a step back after stabbing that guy, the way he holds the sword just feels awkward. Animating weapons is probably one of the harder things to make look natural, you just need to keep in mind how the movement is done and be able to capture the poses correctly, keeping in mind little details like wrist movements to complete the swinging, the wrist itself makes the sword move like 90 or a little more degrees so it's really important to keep in mind.
The naruto animation has really weird pacing overall. some scenes are slow and boring, the action is too quick and scenes end too quickly, it's just not pleasant if you ask me. try to make the scenes have synergy, make the buildup worth the follow up, if he takes 5 seconds just to prepare that attack, make the attack and follow ups last like 10 seconds or something, when he charges the chidori for like 3 seconds and just wastes it in less than one second is kind of a bummer.
tldr; try to familiarize with not so common poses, animation pacing and overall subtle movements to be clear.
