If by RGB you mean it has multiple zones (DRGB) then no the light strip can display one colour at a time that you can select and of course it supports all the effects that Synapse has.
Yes, you need to connect the mouse mat via USB for the RGB lighting to work. It is connected to a USB port on the computer and can also be connected to other USB ports, such as a charger, in which case only the standard lighting will be displayed.
As soon as the pad is connected to a USB "power source", it lights up. Colours can only be changed if Razer Synapse is installed, which is only available for Windows PC.
Hello
You have to plug the mouse pad into a USB in order to be able to change the effects, colour, etc. to change the effects, colour etc. But you have to download the Razer software for that, if you just want to make the thing glow then a power connection via USB without a computer is enough, but that would be a pity because there are cheaper pads without effects etc..
I can't answer that, but I can tell you that I have a rat7 and it works very well, the only little flaw is that the carpet has to be shaped a bit when I took it out of the box and it wasn't quite flat.