Ability to start streaming without "IS NOW LIVE" notification being sent, option to enable manual mode.
Streamer should be able to toggle the default "going live notifications" (push/web/email/etc) so they can test stream briefly. Perhaps an option to send that notification manually once they are sure everything is working.
It is my understanding that partners (and possibly affiliates) can actually run a test stream.
Before anyone brings up "bandwidthtest=true" - Last time I used it there is no video displayed either. This suggestion is for an option that would display video on the channel for testing purposes. (if bandwidthtest=true does show video then I will suggest OBS add a button to toggle this flag )