For the running animation, the back could lean slightly forward. The front leg could use some work too. Due to it being roughly in the same place for the majority of the frames, it doesn't look like it's moving a lot. The back leg looks perfect, so just try to have the front leg moving more like the back leg does.
With the stand > run > stand animation, it looked more like the figure was sliding. Try to have some frames where it looks like the back leg is crossing over the front (so the knee is past the other leg, but the rest might still be behind the figure). That might help with the sliding problem, but foot placement could also use some improvement as the feet twitch around a bit. I think if you improve on those things it will look loads better.
Vegeta animation, there's not much to comment on. Easing looks good there though (the speeding up/slowing down).
With the punch test, it would have looked a lot better if you moved the origin (orange node) because it just stays in the same place even though his legs bend. It looks a bit weird. Rest looks okay at the moment, but definitely remember to move the origin.
Animations in general look okay. I think it's good you're trying these tests and working on improving your movements. If you keep at it you'll start to feel good about your progress. You have potential.
