Hi! So Ill preface this by saying I myself am no means an expert either but I do have some advice I'd give
first, unless it's a purposeful stylistic choice youre making, the stomach animation is exaggerated to the extent it becomes distracting/the focal point of the animation.
second, I'd recommend animating the whole body consistently, specifically the legs, even subtly so the character looks more cohesive and less like a set of independent parts. the shoulder is animated in a way that the arm isnt, which could be improved
hopefully that helps some