One of the things that bugged me is that 3 signatures of yours look like they utilize the same color schemes and the same font choice. Don't mind me, I'm just a fan of making another piece of work look completely different. Also, I happened to notice some jagged lines in your stock images. Perhaps you put too much contrast on them, but I guess that may be your style since the darker more heavily contrasted portions of the signature seem to blend with the lighter portions.
Overall, they're pretty good and I like.
Hay, I'm a fan of borders. When I was making signatures back in the day, we needed them. However, I like Jigglyness's take on them with a signature having either horizontal borders or vertical borders.