this looks great.
but, if the recovery seed uses common words aren't they very easy for some one to guess and 'recover' the keys even without touching your device? they could just guess all combos?

one more thing, I can imagine this in a point of sale at the shops, the USB cable would be a little annoying.
blutooth maybe, but that is not very secure is it.
What about some device on the counter you push the trezor into a slot which lines up the usb and everything correctly.
you could take it out for a sec to check the details, then back in to send the tx.