No. You cannot change the color of the notification light in LG Q6 Plus.
Yes, LG Q6 Plus does have the dedicated MicroSD card slot.
No. LG Q6 Plus is not a waterproof device.
Yes, LG Q6 Plus does have the Corning Gorilla Glass.
No. LG Q6 Plus does have the LED notification light and it also has the Always-On display.