Effects of Milk vs Cream vs Condensed Milk in a no-bake cookie recipe
Using condensed milk would definitely make the cookies much, much sweeter and may not be moist enough in the same volume to make the cookies. Using the condensed milk could require more care on the stove since it would probably be easier to burn. If it browns a bit in the pan it could also impart a burnt sugar/brûlée like flavor, which might add a nice complexity to the recipe.

The cream would just make the cookies a lot more oily, which would probably result in a moister cookie that doesn't harden as well.