I can only comment to the iOS and iPhone5 question. I had my 3Gs paired to my home phone and it would reconnect everytime I was in range. Repaired my iPhone 5 and never had a problem. It reconnects automatically everytime. I've had it for over a month now and never had a connection problem. So I doubt it's the iPhone. I would turn it off and back on though just to be sure.
As far a resetting the factory stereo.. disconnect the battery for a couple minutes.. You can turn the iginition on with it disconnected to fully drain the system.
GL
As far a resetting the factory stereo.. disconnect the battery for a couple minutes.. You can turn the iginition on with it disconnected to fully drain the system.
GL