The master key is largely irrelevant if you have the Owner key.
You can use the owner key to change any key (including owner).
If you ever change your password you can get a new master key using the owner.
Or you don't have to have a master key at all.
It's possible (very easy) to disconnect your keys from the master.
Just change your keys one at a time and don't use the same master to generate them.
thanks!