Idle or offline literally means that the computer is either idle (online and ready to accept connections) or offline (meaning that it's offline or even the Host is not installed at all).
You are probably confusing the idle state with the logged in state. The remote Host can be idle and awaiting your connection but you may not have been connected to it yet. In this case it's a grey monitor and the status is "Idle or offline". Then when you log in to that Host using the Login command, you are "explicitly" connected to that Host in which case the icon turns to a green monitor.
The Agent is an application and runs under the current account. I'm not sure if it's capable to also work on the lock screen. You would probably want to use the Host instead, as it runs as a system service and grants total control.
The last time it took them about 4 maybe 5 days to approve. Now we see that there is yet another iOS update (9.0.2) and we will be testing the program against that update also once we release the current app update. And it's all over again, if Apple decides once again to release another update.
That would be a potential security hole :) The Viewer, as an application, is never locked. So imagine a situation where a stranger gets access to your computer for a short while (like when you left for a lunch) and peeks into your connection properties.