No devices can not pass the CTS and look/feel significantly different. Vendors sign up to Google's non-fragmentation agreement which means that although you can put a slick veneer over the top (but doesn't effect functionality). You cannot add new cool stuff. For example you wouldn't have been able to add your own NFC payment system to ICS ahead of other vendors. You also can't add your own APIs to power your own devices etc.
sorry, but that is simply not true. CTS does only test for API compability.
If you decide that you want to license Google's Apps for Android for your device, then Google will try to use all its power to prevent you from using a competing technology like NFC. That is how software licensing works, and who comes out on top is usually the one with the most powerful decision.
But this has nothing to do with Android or the Compability test suite. It also does not interfere with any plan to use a unique look&feel. You don't have to license Android.