1) The flex sensors are far too unreliable and not a very accurate way to get good control information from the metal slapping quickly.
2) The contact mic offers a great wealth of information, more so that I initially gave it credit for. As should be expected, the amplitude gives a great idea of how hard the membrane is slapped, and the frequency correlates to how much length is given off the end of the table. The majority of my time thus far has been devoted to cleaning up the signal to be able to extract the frequency information, but it is my belief that with a bit more work and research I will be able to get something more proportional to the physical situation at hand.
3) Radio frequency content evaluation... still to come
Lastly, I have created a 3D model of what the device will look like and will begin a first prototype of a single slap tomorrow in shop.