Is there a way to get the "windows" button to work with the Kicker menu?

Right click on kickoff buton, Configuration then go to Desktop Shorcut and select the key that you want use.

But, you can't select "windows" or also caled "meta" or "super", so, you can use another combination Exmp: "Meta + Z"

As far as I know, the "Win" key is a "modifier" key like Alt or Ctrl, and as such it cannot be used "alone", you need to use it in combination with other key(s).

I believe hacks can be implemented using Xmodmap that make the Windows key function as an arbitary key instead. Note that these remove your ability to use other keys with it.