Two quick questions:
-is it bad to have the keyboard backlight always on? Will it somehow burn out the little lights?
-how much less battery power will I lose if I have the backlight always on? (I use Labtick).
I think you will lose more battery power if you have the keyboard light on. However, it's not significant. It might make 5-10 minutes difference in the grand scheme of things.
You don't have to take my word for it. Try it out for yourself.