Pro tip: Turn off the "Simple Password" option, then enter a new password that consists of only numbers. The password prompt will then still be the nice 10-digit keypad rather than the full keyboard, but the passcode can be any length.
Yes. If you have digits only, you get a freetext field, but with the digits only keypad.
Even more fun: if you give a four-digit passcode for the non-simple passcode, it turns on the 'simple passcode' option again, which means that you can't have a four-digit passcode without telling the length of the code.