In regards to the idea of stepping down the security on the withdraw address locking I had this idea:

When signing up you could make it (compulsory or optional) to add a 2step like phrase in which you choose a phrase (that cannot be your password) to change certain things on your account, like changing the withdrawal address, this would give a good layer of security but at the same time giving the user an easy way to change their withdrawal address.

What do you think?