Can you put fondant or royal icing decorations on a cream cheese icing cake?? You know since it has to be kept in the fridge. Many people love cream cheese icing but I find it very hard to decorate with.

Not sure about RI but certainly fondant.
I would not put any RI on cr ch & in the frig - all three Nope, that's not going to work.

How long in the fridge? MMF will definitely last overnight or so but I had some in the fridge for a few days and the dark colors ran, they just got tooooo moist. Irrelevant to the cream cheese of course, but rather because of the refrigeration. Keeping them uncovered would probably have been a better choice though, since the fridge actually tends to dry out your food...I think I erred by keeping them in a sealed container, so the moisture was locked in tight . Live and learn.

Of course if you are using Satin Ice it's not even a concern; I am only speaking for MMF.

Thanks for the tip on RI kakeladi, I had no idea!

I use Fondant on Stabilized Creamcheese frosting all the time. It needs to be refrigerated YES but I am just saying I have never had a problem (I use Satin Ice fondant) it has never run on me ever. But that's just my experience. Good luck.