@davidw - that is meant to refer to not selling or redistributing the icon pack as a whole - you are more than welcome to use it in any open source redistributed work.
That would include stripping out everything but the icons and selling them.
So if the license requires all accompanying code/assets to be under similar licenses, that could prevent use of your icons. I think that's the case under the GPL? Not really sure anymore.
e: After doing a bit more reading, I believe I was wrong. As long as the icons aren't somehow compiled into the binary, there are no license problems.
Public Domain and CCZero would be a very efficient way to quiet people's fears about what they can't do with this icon set, without alarming them that they need Legal Advice to build their app. You've tried to trim down the restrictions to almost nothing, but we have an established protocol to encompass all uses. Why not go all the way?