A:Must have? No. Very Very good to have? Absolutely. New controllers do NOT come with a charging cable.
A:No, the ports on the bottom of the controllers are different.
Q:Does it support double charge?
A:Yes, it will double charge your DualSense controller from top TYPE C and bottom charging dock point.
A: Yes it does have indicator lights as you can see from the photo. And it looks pretty cool in dark.