If you're a bride, it shouldn't be your job to think of all of the details that are necessary for each professional to get their job done. You should be able to hire someone who has enough experience to know what needs to be double-checked, and let them take care of it.
I recently wrote about delivering a wedding cake to an outdoor location on a hot day, and how I had insisted that the cake be covered in fondant. Everything went fine, but it could have been a lot different if I hadn't had some experience with the venue. First, this is the driveway that I had to go down to get to the reception site. This was literally two miles (I measured it on the way back) of large gravel and ruts, and it was the kind of driving that makes your fillings rattle. You either have to decide to go really fast and hope that it's over soon, or go really slow and hope that the vibration of the car doesn't shake the cake apart. I opted for really slow. (On a side note, when mapquest says "road partially unpaved" this is what they mean.)
Next, the issue of the heat...The bride had arranged for the cake to be inside the house until after the beginning of the reception, so that it would stay cooler. Even inside the house, though, it was about 85 degrees, no air conditioning, and I was sweating from the humidity just setting the cake up.
Those were the two major issues of the day, but neither one bothered me. Why? Because I'd delivered cakes to that location many times before, and I already knew about the road and the lack of air conditioning. I took the cake unassembled and set it up on site, so the shaking of the car wouldn't bother it, and I insisted that the cake be covered in fondant even if it was going to be inside for a portion of the time. I was ready for that particular location's quirks, and I knew how to handle them because I had experience delivering cakes there before.
If I had never been out there, the bride would have told me that the house was cool enough to store a buttercream-covered cake, I would have taken it there assembled, it would have shaken to pieces by the time I got there, then whatever was still standing would have melted.
So for all you brides out there...Make sure that whoever you hire has the experience needed to accomplish what you hired them to do. Whether that's someone who's been in business for twenty years and knows all the tricks in the book, or someone who's been in business for a year but has a lot of experience working with your venue, check them out. You don't want to be the experiment/portfolio-builder!