This advice is free, so remember that you get what you pay for. When FUNC is active, the tuning knob will adjust brightness again. You can restore automatic control by repeating step 1. Manual is fuzzy on this feature. When either band's squelch opens, the other band is moved into the primary frequency display and the transmitter keys.
Audio link appears to be speaker to mike.
Exit crossband repeat mode by repeating steps 2 and 3 above. This number is number of minutes for the timeout timer. The factory default appears to be 15 minutes. The mic element stays live while in xband operation. They just did not want to re-design the mic again within a short period of time.