You would not be able to have your firearms delivered to your job. They can only be delivered to the address on your license.
When you decide you don't want to use your 03 any longer, just stop buying and hold on to the license. No need to return it or your log to the BATFE.
The only requirement for taking your firearms to France is to:
#1- Never fire them.
#2- Drop all of them.
#3- Either run or surrender.