How does the "type OTP" thing work? There are only two buttons, right? I didn't really understand that part.

BTW confirming each address+output might be confusing in the case of the change output. Maybe you can suppress that one?

Just re-iterating my hope that you make the firmware split (fixed bootloader and reflashable main part), that way, when the payment protocol work is progressing it will be a smooth upgrade to have Trezors show names instead of addresses.