Hi Mark,
In regards to your second question about modifying the dot-box, it is easy to open and it has an mDot built in with the form factor seen at this link.
https://developer.mbed.org/platforms/MTS-mDot-F411
So you would have easy access to the available peripherals of the mDot. Keep in mind that you have to manage your added component with the on board sensors.
Leon