I recently spent time in the home of my daughter and grandson. We always like to do some project together. This visit my daughter and grandson put together a batch of dough for gingerbread cookies, and even though our decorating efforts are not 'professional' we had a great time together. (Check out his t-shirt!)
You can find a recipe here or here.
We made royal icing using powdered egg whites. The 'old' recipe used in the 'olden days' used raw egg white but it is generally recommended today not to do that due to the possibility of salmonella.
On the other hand, it would be a simple matter to make regular frosting from powdered sugar for your decorating process.
Go for it!