is there a tag for the autounattended.xml to have it skip key input?

yes, you can do this with WAIK

If you specify a product key in the windowsPE configuration pass with ProductKey, then Windows welcome will prompt for a product key. If you specify the ProductKey setting during the specialize pass, then Windows Welcome will not prompt for a product key.

So .. I use the 'Specialize' pass ... but you still need a valid ProductKey .. or it will reject. (That's what I know)

If you remove the ProductKey Value in all locations of your answer file it should skip it altogether. You will begin you install in the 30 or 60 day "demo" mode and need to activate it with your license number during that time to maintain full functionality.

I tried that and at "specialize" pass and it didn't work.