I will be making a 3 tier cake and my problem is not stacking the cakes, but taking them apart to cut. Since the cake will be sitting out for a while, the frosting obviously will become soft and my concern is that the frosting on the middle and bottom layers will come off when the layer above is removed which would make for a very messy looking serving. I would hate to spend time refrosting before slicing. Is there a trick to this problem or do I refrost? I appreciate any suggestions.

I'm not sure I get what you're saying, but you could put each tier on cake boards and very subtly hide them with the icing borders. When you want to cut the cake, you can just pick it up from the cake board and cut like that. That should keep the icing in tact and not leave a mess. Is this what you mean?