A:
Range appears to be about the same as for the handsets.
You CAN switch lines while using the headset by selecting the line on the base unit.
You CANNOT switch lines on the headset alone, nor by using a handset. Most features (line select, mute, redial, etc.) can ONLY be accessed with the headset by using the base unit.
You CAN use a handset to dial by conferencing into the same line the headset is connected to.
With the headset alone (when you're away from the base unit), you can only answer an incoming call on whichever line is ringing, or connect to line 1 (or line 2 if line 1 is already in use).
Answered on 4/20/2010 by suboptimal from maine