This looks pretty great, and intuitive. I'm sure it wasn't your intention, but I don't have windows (or mac), so I ran this in wine. It's actually working alright! Things aren't laid out perfectly, but it's completely usable. One thing that tripped me up is that it just puts the gcode next to the image. I don't have my laser up and running yet, but the gcode looks good to my eyes.
Have you considered sharing the source code on github or bitbucket or something similar? You might be surprised at the support you'd get there, and maybe even find some developers interested in submitting fixes or improvements.