The summary license says that you can't redistribute the graphics. Admittedly, I'm used to licenses such as GPL where including the file in an app's package file would be "redistribution" - it looks like you mean "no redistribution of JUST the graphics file" which could perhaps be clearer.

Also, the license seems really concerned with not putting any of your graphics in a theme or template. Why is this? I'd consider offering a licensing option which permits this, perhaps on a different pricing structure.

You say can't use in/on a paid product, but can use in a paid service. That's confusing because I'd think of my paid website service AS my product - I think you might mean "no use on physical goods for sale" which is another restriction I don't particularly understand but okay. Again that might be something to offer an option for.