Good for you Lauren, for your trial runs. I cannot answer all of your questions, but I will address a couple.

I sliced my wedding cake layers before I put them in the freezer. I filled each cake pan so they would cook "over the top" and then used a very long knife to slice off the excess when each layer was still in the cake pan. That gave me layers that were exactly the same height. I would then apply a crumb frost to each cake piece before I put them in the freezer.

After a few near catastrophies I designed my cakes so they could be assembled after delivered to the party site. I definitely preferred assembling my cakes AFTER I arrived at the reception site. I would also have a friend or two ride in the car with me to keep an eye on the cakes as I drove to the reception.

I always bought cake boxes so each layer could be put protected while in transit.

If you are using pedistals between the layers you definitely want to assemble after delivered.

I always took extra frosting and extra flowers with me to the party site to enable me to fix areas that were bumped.

One more tip. Part of your cake's support system will be touching the top of each lower layer. It is a very good idea to put a layer of powdered sugar, or flaked coconut, between the support sytem and the top of the lower layer. I hope I am explaining this clearly. This way your frosting will not be pulled up when you remove the support platter.

Keep us posted Lauren. Kel