You, sir, are correct.
I decided to call again and asked to speak to a technician "who knows what he's doing".
He confirmed that the battery in the key has nothing to do with the immobilising system. It's only for central locking.
He was also willing to try and code my old key (which i believe and HOPE just had a bad day and lost the code), and if he can't he'll code a blank key for me they have in stock, which is BTW way cheaper than ordering a key from France.
Thus, you were correct in that the later models can be programmed with a blank key, specifically the VIN: BB2V...
Just goes to show, if someone immediately says: "You'll have to order from France" before familiarising himself with the car/situation first, or also by not EXPLAINING the scenario (ie. causes, remedies, etc.) to the paying dumb customer (me), they give mechanics and technicians a bad name.
I'm beginning to suspect mechanics are worse than lawyers...
Thanks again for the info. Now (hopefully) i don't have to wait for the French
How do you know so much about Renault? Had some problems of your own?