First one..
Lay off on the scan lines a bit, it is making the sig too dark, and hiding what is under it, you can lower the opacity. or maybe set it to a different layer type, or space it out just a bit more, but still lower the opacity a bit. The text looks horrible, it looks a bit like halo text, you should try to locate the text that has more shape to it, or use the one that only has a border, I will try to find it for you, if you want, and host it on here for you.
Signature 2
Well, I have to say, the scan lines (if they are scan lines, they look kinda cross hatchy) are good, but maybe make spaces a bit bigger, and is that ... a like mosiac pixel thing on the bottom right corner(sharpened) , if it is, you should brigten that up more, because I love that style, if you don't know what i am talking about here is an example:
Now do you know what i mean?
The little boxes on the left.. I think you should of kept that effect more..
The text is not very good, It could be better, but is sufficiant.
Numoro (spanish i think) toi (french i think)
Well, it is great! But where is your name? Could it possibly be ripped? Or am i just missing out the name part, sorry if it wasnt, and if i am accusing you falsly.
Things that you should work on on that sig are:
You see that effect by the right arm? You should add that more around the image, i think its kind of a smudge sharpened. But i am not sure. It looks nice with the signature, and you should most definatly size it down!
Add some text, maybe just like basic text, all you need is like veredana with a nice design around it, then voila your signature is completed.
Number Four..
Hm...
Abstract brush spammage? Tell me if i am wrong, it seems a bit dark, kind of blurred, and the text could be more.. inviting. It doesnt really catch my eye.