As stated above, the main cause of a Wrist Drop is overuse of the wrist whether it be with occupation or sports. Wrist drop may also be caused due to a trauma to the radial nerve by way of a cut or stab wound, or if a person suffers a gunshot wound to the wrist affecting directly the radial nerve. Another cause for a Wrist Drop is some sort of injury to the joint in the wrist or elbow resulting in persistent swelling of the elbow.
A. It's not a great idea. Cream tends to separate when frozen, and while you can freeze a carton of cream (double-wrapping in freezer bags is recommended), you can also shake it thoroughly after it thaws to reblend it (although it will not be as good as new).
It has to do with the size of your centers and the temperature of your freezer. I assume you want to dip the small centers of cream into warm chocolate, so they need to absolutely frozen solid. For that it may take 6-8 hours or possibly less, depending, like I wrote, on the temperature of your freezer. You have to play this one by ear. Since you posted your query yesterday, I hope you have already frozen the cream.