I am assuming that a more dense (ie pound cake) type of cake would be better for stacking and carving cakes? Would anyone know if this is true and if so how do you create a more moist, dense cake from a regular recipe?

For carving cakes, yes denser is better. As for stacking cakes, I use whatever cake the client wants, as long as there are proper supports, almost any type of cake will do. Sorry, but can't help you with your last question on how to change a recipe to make it dense. I would just use a dense type of recipe.