I plan on putting the AppGameKit Logokit with each game I sell. Instead of the words "Made with" how about "Powered by" or "Powered with".

I imagine as long as the website: http://www.appgamekit.com/ and the logo is visible the rest shouldn't matter.

All of this is now optional, so you don't have to do it but it would be nice to help spread the word about AGK. It's fine to say Powered by or Powered with.

Would it be possible to just get a Transparent Background version of the AppGameKit Logo without the wording?

Yes, will see if I can sort one out.

There's one created in your My Documents directory under AGK/(your app path). It's decent size and has transparency.

It's called interpreter-logo.png.