You mentione...
I have Tor running on the USBArmory by InversePath ( http://inversepath.com/usbarmory.html ) and have a microSD form factor card made by Swissbit ( www.swissbit.com/products/security-products/overwiev/security-products-overview/ ) up and running on it.
Good that USBarmory could provide even tor binaries over a usb mass storage fs for the host to run. Or even run the tor process and network itself as you say.
However how is "pin" on swissbit enabled? If it goes from the host (say via ssh or keyboard or some device or app) through usb port through armory to swissbit, that is never secure. If it goes from external pad through GPIO on armory to swissbit, that will not be secure if host can in any way snoop on armory, or can use or modify code on the armory to do that and report the armory core / bus data back to the host. If swissbit card itself had external I/O for "pin" ops, that would be secure.