Wow, nice post. What it does not say is how to read those notes. Since you said that Steemit uses the posting key to encrypt them, I decided to guess that I have to log out, then log back in with just the posting key, then go find my active key to send a response (send 0.001 steem).
With that unstated tid but, it works really well.
Also: It cannot be stated enough that nobody should be logging in with an owner private key (master key). That should be kept off line.