I say things on PC that I would NEVER say on fb. Though my image becomes less and less of a worry as I age because most of my career opportunities have come and gone--you do have to be careful what you post on fb because a future employer or client could look. I have just accepted that I can only hint to my "real" fb friends my deepest issues. We have said that we are looking forward to getting together again someday (two friends from my youth who live on the other side of the country). This is why fb is not as good as seeing friends face to face IRL. It beats being isolated though. You are in a conundrum. Perhaps keep these "friends" but ditch them when you no longer work where you are now. Chances are, you will not have that job forever.....

Also, consider this, if you are ever laid off (happens so much nowadays) having your boss as a fb friend will make it easier to reach out to him if you need a reference when looking for another job......