They are, for the most part, too dark. They seem rushed and very poorly made, and rely on heavy use of stocks and images that you did not create (which makes this c/p, not art). Your focals are poorly placed (and in the case of the AC signature, blurred, which is always a no-no) and it seems like all of them are of a very poor image quality (did you save them as .jpgs?).
In other words, you have a very, very long way to go before you can call these signatures.