I have a couple of logistical questions about using multiple X/Y games with a particular 3DS:
1. Would using two copies of the same game (e.g., 2X or 2Y) on the same 3DS cause any problems? In this case, both are cartridge versions, so I'm assuming all of the relevant data should be on the cartridges themselves, but I don't know if it would mess up settings, online stuff, etc.
2. How does using multiple X/Y games (e.g., one X and one Y, or multiple copies of the same game) affect PSS settings, friend safari lists, etc.? For example, if I've been online at the same time as other people on my friend list in X and have unlocked all of their safari Pokémon, will I need to be online at the same time with them on Y to give my Y game access to their safari Pokémon as well? Will they lose access to my third safari Pokémon (unlocked for them by seeing me online in my completed X game) if they see me online on the same 3DS from an incomplete Y file?
3. Are there any other issues (or any issues at all) that I should be aware of that could result from using multiple Pokémon games online from the same 3DS?
4. What are the consequences of switching between two 3DSs? When I accidently did it with X back in October, I seem to recall issues with berry growth, store stocks, etc., for a couple of days, but are there any longer-term/more significant side-effects that I'm forgetting?