Basically no to everything, ahri diff is yes and also multi target vs single target. What about GA Ivern?
Ironically you're going to have to use cheats to remove it (or you can remove it form memory but cheats are easier) and it will get worse if you keep it there. I don't know what's causing them exactly.
The latios is obviosuly a bug I don't know why it is roaming before it gets activated, I honestly don't know why people catch it and of course it has no moves IT'S NOT SUPPOSED TO EXIST.
Regarding tahm, he doesn't learn charm so he shouldn't have it. Where did you encounter this?