Hello,
Hope you are well in the bless of God. I can say boldly that I am the right developer you are looking for. Because, I have +10years of experience in PHP and +5years of experience Drupal. I had developed more than 50s of website in Drupal. I have experience in Ubercart, Organic group, Simple newsletter, managing multi domain architecture, multi language, panels, layouts, views and VBO, Rules and components, custom modules, custom themes, etc.
So I know exactly the perfect solution you need.
The only thing that I did not understand is #4 Admins need to be able to copy/repeat an order. What is the process you want for #4?
Please, message me if you want a personal Interview and discuss with me.
It will be an honor for me if you hire me to do this job.
Thanks