Hi,
even though i like your plot and the mechanics you have used so far i am rather putout by the stuff you either didnt mention or maybe forgot ...
like harry doesn't know any french, or has he learned some from fleur (it is possible just not mentioned ;)), i've been to paris and believe me, even though the larger restaurants and hotels have staff that do speak english, finding someone without the language will be quite hard ... not to mention settling any problems at gringotts ...
a 2nd huge logical flaw (at least for me) was the fact that harry apparated to france without any money (you didn't even mention if he had any in the first place, i myself don't have large amounts of money sitting in a home, i normally have like 5 pounds in my pocket and thats about it ... a 16 yearold will have less, even if he had more, even a cheap hotel for a week and steak dinner will cost some more than the cash most ppl his age have in their pocket), also canon harry is obviously a teen (as you didn't describe him i assume he looks the same in your story), why didn't the hotel staff or the restaurant staff mention this and ask either where his parents or guardians are or how he aquired so much money ... it would normally raise some questions ...
another thing is that even if harry had money, he'd have to exchange it for at that time franc ...
i really don't want to tear apart your story but those two things really stuck me as odd ;)
hope to read more from you :D
regards