I'll try, and I'll try to make it fast.
First, yes, there will be a lock on the phone; then there will be underlying security requirements to make sure that everything in there is containerized, unassailable, and encrypted. Remember, we're effectively creating another version of a Visa card or a MasterCard. Behind that are the payments networks with their zero liability. If your phone, for some strange reason, is stolen and used, the same underlying zero liability rules will apply to a card on the phone that apply to a plastic card today.