If you are professional or trying to break into the professional world, NO facebook is not even close, it's not even safe and secure... ANYONE can right click and download your images, and people have been known to steal images and post them as their own on facebook
While I agree with you on the facebook angle, the "safe and secure" part is false.
You say "anyone can right click and download your images" on Facebook. This is NOT specific to facebook. There is NO WAY to prevent a user from copying an image displayed in a browser. There are MANY techniques out there to try and prevent it, and NONE work.
I've seen many sites waste a ton of time trying to prevent "right-click and save", and as a curiosity (I was researching this for myself a while ago) bypassing these schemes is often trivial. Something as simple as a screen capture will defeat EVERY SINGLE METHOD I've seen.
As a result, I came to the conclusion that trying to prevent right-click and save is a complete and utter waste of time, and most of the biggest sites on the net seem to agree with me.