First off I would like to say Welcome to the Void :]
Now for the C&C
The smudging is to obvious and what I mean by that is it doesn't go with the background unless you used the smudging as a "Speed" kind of effect.
The text needs some work because it draws to much attention away from the focal and its blocking it.
Simple text and white can be effective if you use it right.
When making a signature you wanna take all these into consideration Depth, Focal, Composition.
Depth is doing little or big stuff to the picture to make it more real/better
EX-
Blurring the background so it shows the focal. just don't little stuff like that
Focal is when you have one or a few certain points (like the face) to focus on that so lets say you add a light in his eyes that it stands out from the rest of the signature.
or using the hand in your signature which you did so what you should do is use Filter-Render-Lighting Effects and set it to Omni, click where your focal is and lower the opacity.
Compostion is basically if you use brushes, c4ds, bubble c4ds then using that it all comes together.
You probally already know this but just making sure :P