The Game Icon image used by official ambassador games is the title screen. Wait for tomorrow for the next version of the injector, because I fix on it a banner image resize bug.
The injector provides a text banner creator, but it's not accurate as the official VC ones. The proper way to make these text banner is with Photoshop or Gimp. Check
this thread, it explains how to do official looking VC injects using my injectors, even the text banner thing. If you're not able to get the text banners properly, then tell me and I'll make them for you.
Also, to make 3rd gen Pokemon Games to save well, you have to follow
this guide. Again, tell me by PM if you can't achieve this for any reason. I have all the 1-7 generation Pokémon games on my 3DS, so I can help you.
The border color is like that due to the color customization. I had to turn it gray and then find a custom purple color which will turn the gray border to purple, and so on with any color (using alpha blending). If you find a more accurate purple color, tell me and I'll going to make it default.
Only apply it if the game doesn't save and load properly.
Fixed in the next version (tomorrow), sorry!