Sorry for the delay, i've been on holiday! thanks @mayer for the heads up on this question.
Apple sell the touch ID as part of the logic board, so it is very much like iOS devices in that sense. You cannot swap the touch ID on its own without having a matching logic board for security.
The keyboard has its own dedicated socket, so although it is much more complicated a design to earlier models, the keyboard is not mapped or altered (as some MacBook air models are) by the logic an IC.
Saying that, i've not had the need to strip out the keyboard from the top case chassis yet, so haven't experimented with its removal yet. But just be aware, the keycaps '''are''' different to the 12" models. We've classed them as a new type on our system because the clips are different thicknesses and have different alignment to the 12" versions. (most dont know this, but there are actually 2 different colour keycaps, so when you are ordering keyboards, try and specify if you are getting the space grey, or the silver/gold keyboard for the 12", or the space grey or silver version in the 13" and 15" 2016/17 models. its a very slight colour difference, but enough to notice if you have one of each keycap next to each other.