you mean the little dot?
if no light = photo mode
static red light = video mode, will blink when start recording

the rounded one at power button,
purple 100-90% battery
blue = good
red = be prepared spare batt
(usually on my usage, estimated 1hr 30min+ constant recording 1080, 30fps)
yesterday transferred my 400mb video to my hp
looked at speed, average 800kbps - 2mbps
but very unstable, sometimes 0kb for a few seconds and resumed