Problem to change the country of my Apple Store?
I had this problem as well. I thought of maintaining 2 accounts (one for each country) but that just seemed clunky, so I opted for having just one in my "home" country (USA). Which is what I'm guessing you did too.

This was a couple years ago, but I remember contacting iTunes Support and explaining the situation. They basically said it was OK to go either way, but there's no bending the rules about what country the account is paid from, and you're still liable for all taxes etc. as if you were in the country you choose.

That doesn't answer your question yet, but since I have credit cards in neither country, I've had to get a bit creative. I've ended up funding all my iTunes and App Store purchases with gift cards.

If iTunes/App Store gift cards are available in France, you're pretty much set. Get a friend or relative in France to buy the card and send you the code. Set the iTunes account up using the gift card.

If you don't have anyone in France to buy you cards, I'm sure there are sites where cards are sold by third parties (and the codes delivered digitally).

I don't know of any for France, but I've used one to get my US cards and it worked perfectly. Do expect them to charge a commission on top of the value of the card. They have to stay in business too.

If gift cards aren't available for France then this option won't work for you.

You might be asking yourself how I bought the US gift card if I don't have a CC in the country where I am now. I have a prepaid VISA debit card here. Many sites will accept this as a credit card, so I used that to buy the iTunes gift card.

Yes, a bit complicated, but it occurs to me that, if this type of VISA debit card is available in France, you could just get one of those and use it in lieu of a credit card.

I have no idea if the France iTunes store will accept it though, but the fees for creating a card like that are usually like $10US upfront, nothing recurring (which is what I assume you're trying to avoid by not having a card in France), and they last for 2 years or more. So that might be worth a shot.

Hope you figure something out. Let us know what you end up doing.

PS: I helped a friend with this exact problem a couple months ago, actually walking them through the sign up. I noticed that since he was connecting from a non-US IP, it kept trying to sign up for the local store, even though the gift card was for the US store.

The solution is to use a VPN or proxy that makes it look like you're connecting from the country the card is for. This only happens if you're creating a brand new account with a card, and it only happens the first time.

Once the account was set up it continued working flawlessly WITHOUT the VPN, even when entering newly bought cards. I suspect this is just Apple trying to keep people from doing silly things, the same way you can't paste a password when changing your Apple ID password. It's a shame for those of us using password managers though...