Commercial/professional photography requires a permit. My efforts are a long way from professional, though I have noticed that the jobsworths who police this sort of thing are poor judges, and tend to make an assessment based on the size of your camera and their mood at the time.
My question was more around do people think that the model would object (guess there's a way to find out...) and would onlookers be offended?
The first part of the question is easily answered. I think you understand how..
The second part of the question is more difficult to answer. Offence is cultural and I have no understanding of how this sort of thing would be appreciated in France. In some cultures there may be very little between, to use phrases already mentioned, "humping a grave" being sexually offensive and "angelic prayer" which could be interpreted as culturally exploitative (see Native American headdress discussions
ad nauseum) and religiously insensitive depending on the exact details and circumstances involved.
If Pere Lachaise is conveniently located for you, then guess you may be in the better position to determine the local attitudes? I've photographed there, but never with a model.
Once you start adding a model, tripod and lights/reflectors it becomes increasingly hard to justify the difference between a commercial shoot and a portfolio shoot with commercial production values. Even more so if you are also a pro and it's then even more difficult to differentiate between a direct commercial shoot and a portfolio shoot with undeniable commercial value to your business.
I think you'd need to me more specific about the details if you wanted a specific answer.