1.How far from the receiver is still working fine?
As far as 24 feet and the mouse still works

2.Can the scroller be pushed down and used as a button?
When you push it down you get auto scroll mode, screen scrolls wherever you point. Click again to turn it off.

3.is this compatible with Chromebook?
if it has a USB port I am sure this mouse should work. Just plug the nano receiver into the USB port and switch on the mouse.

4.Is it compatible with Apple iMac and Apple MacBook?
OSX Snow Leopard, Lion, Mountain Lion and Mavericks. It should run on all Macs with those versions of OSX.

5.Can another device be added to the receiver that comes with this mouse?
No

6.How to trun off the PW-2 LED color?
Long press the DPI key about 3 seconds.(when the PW-2 macro application was running, the LED light can not be truned off, please make sure you have exit the application)

7.How to switch the PW-2 LED light color?
Install the PW-2 macro software on your PC. switch setting into "LED SETUP". select the 'static'. then the color can be switched.(the color turns with the DPI changing)