3DS games are region locked, a 'French' one (actually an EU one) will work on any European 3DS, and also the Australian one.
You'd have to use system transfer to migrate your ID from the 3DS to the 3DS XL before you can access your downloaded games on it.
You can play Nintendo DS and DSi games on the 3ds, but the 3ds doesn't have a slot on the bottom for Gameboy games.
No, you can play regular DS games on a 3DS too.
yes
You buy ds or 3ds games and then put them in your 3ds.
3DS games do not have friend codes, it is the friend code of the 3DS itself that you use, to be able to play multiplayer on a 3DS game.
Yes, you can. However, since the Nintendo 3DS are region locked, the European 3DS will not be able to play North American 3DS games.
No, 3DS games can only be played on the 3DS.
yes
There could be a few factors that causes this to happen: - The 3DS needs to have the wireless slider turned on - The NDS cannot play 3DS games so it will not connect if the 3DS is playing 3D games - Some games require both consoles to have the gamecard in order to link. (cannot use DS Download Play)
Yes, it does. There are Nintendo 3DS games that are exclusively for the 3DS family.
You need an Action Replay 3DS, other versions won't work on it - note that it is built to work on regular DS games, there isn't a device for actual 3DS games yet.