I need to bake and decorate a 16 base cake. This is a lot bigger than Im use to so I need a few pointers to help me out. Usually I use 3/16 foam core board under my tiers. Is this going to be strong enough for this tier? If not what would you suggest I use? How do you move the layers as you fill the cake so they dont break on you? Any help would be greatly appreciated.

I'm not much help with the foam core questions but I can answer your question about moving the layers so they don't break to fill them! Here's a video by Sweetwise. Around the 6 minute mark is how she explains exactly how to move a large cake without it breaking while you're filling. Her videos have helped me so much!

Regarding your base, I would use something stronger, because this cake is going to have some weight. When I do a cake of 3 or more tiers, I use a 1/2- in. plywood board to support the weight. With this size board, I know my cake will be properly supported, especially for transport!

Sweet mother of God, don't rely on a thin piece of foam in place of a board.

Great video!

I use 3/4 inch foam core and put it in a 1/2 inck square of plywood for transport