when stacking a cake upon a cake and you place wooden sticks does the icing from the layer the top tier is going to be cut does the icing from the bottom tier come off as you lift the top tier off?

Welcome to Cake Central. There is an article about assembling a stacked cake in the articles section.

Using dowels to support the stack is important. There are ways to prevent the icing from sticking to the layer above: use extra powdered sugar in the center of the cake between the dowels, or shredded coconut can be used (watch for allergies)

I prefer the two to partially stick together, it adds stability to the tiers and helps prevent slipping. You are going to cut it anyway, so it doesn't really matter a lot.

I am the same way...I use a crusting buttercream so the cakes don't stick a LOT, but I like them to stick alittle to add stability. Sometimes I will even add some buttercream to MAKE them stick!! Nobody really notices once you cut the cake...