Disconnecting charger while Macbook Pro Retina is still turned on Is it safe to disconnect (unplug the charger from) my Macbook Pro Retina 13" while the computer is turned on and running?
Absolutely it is safe.

It has been designed for that, it does not have a locked in plug, but a magnetically coupled plug for that reason.

I have done that on purpose or by accident (tripping over the cable) many times without problems.