is it that difficult to flip an image? ah, whatever. you probably just uploaded without flipping it, and by the time you noticed it was too late
your proportions on the weapons are very good, but the arms, legs, and head are all in different proportions. your perspective is fine, but you need to basically just thicken up the arms and legs and make em shorter. another thing to remember is that minifigs have FAT heads. go ahead and draw em that way.