LOL...to be totally honest, I think you're thinking about this way too much. And a hook is a kind of needle - I crochet too, they weren't wrong in calling it a needle. I also think they were referring to the length of the needle and not the hook on the end - I can picture it in my head but I don't think I can describe it well. 4a hair also does not have to be clearly defined - if you have a round coil pattern, you have a curl pattern. I haven't seen your hair but by your description I would call you 4a. Whether your hair looks defined and clumps together depends on texture/density.