I think that a good writer could work the tragedies and triumphs and dangers of early modern motor racing into an interesting narrative - conflict of desires, conscience, that sort of thing. The fact that Helle-Nice spent a good proportion of her life not quite following the moral code of her time could make this into something quite compelling. Bringing in Violette Morris as a character might work, too.
A French director, I feel, would be appropriate.
I think you're right, but then we'd expect to have the Eiffel Tower visible in most of the backgrounds. The girl was a bit of a goer in her time, we've seen a few of her "artistic" poses, and threesomes were rumoured among other things, so at the very least it would be PG.