I have not come across this particular situation. However, based on my own BMQ experience, I would say you will be a part of the group as much as anyone else there. We have guys and girls, short and tall, various levels of fitness, aptitude and physical fitness, and everyone is part of the team. This is something that's highly emphasized in basic training, and candidates begin to embrace this concept fairly quick.
As for being naked around others. I cannot speak for how showers are done at Reg Force BMQ in St Jean, but at my PRes BMQ we hit the showers together. There are still individual shower stalls so you can preserve your privacy. However, in the interest of saving time (as we are always in a hurry because we have to meet a timing), people give up on privacy and you see a lot of naked dudes in the change area.
Whether you choose to get naked around others or not, I would think you will neither be unsafe nor be shunned. If by chance you do experience that, you can address it with your instructors and they should address the issue quickly. There are also formal actions you can take if you come across harassment, as you will learn at BMQ.
Think positive and go for it.