The blurriness is the result of antialiasing. I start with an EPS; can you tell me how to convert this without running into that problem? I'm afraid I'm not very good at anything graphical.
Often it requires a bit of manual hinting. For example, [1] was just resizing the vector and allowing antialiasing to do its thing, and [2] is the result of resizing it and then dragging vertices to pixel or half-pixels.