#4 can it be used in a stereo set up with two?
Yes it can. Technically, with 2 drivers in each unit, you are already playing in stereo but, with so little separation it's not noticeable. If you purchase 2 JBL speakers you link them together. At that time they will be each playing stereo. I downloaded the JBL app for Android from Google Play. When the speakers are playing you open the app and select "Stereo" so that one speaker will be assigned music from the right channel and the other will play the left channel. The app also allows you to reassign right/left channels to the other speaker.