Oh wow, even better! Yeah I guess you can't reset then. Lol I guess you're stuck being whoever gave you the DS. eShop accounts are directly linked with your NNID, so that person's account made the purchase, not the system itself. You can try to see if you can get a transfer by calling the support line if you're lucky, but then you would still lose your ORAS data. Tough break there... I would still recommend going through the settings both on the system and on the eShop though, change what you can to your liking, and make sure that you aren't using someone else's credit card info or something ridiculous like that. Pokebank just lets you store pokemon from the game on what are basically online PC Boxes. So, if you take the previous user's Pokémon and put them on there, you could put them back on the new save file you start. So basically you can steal them. I also used to do this with Transfer in the older games. It was just supposed to be a joke.
Yeah, unfortunately it is a factor. That doesn't sound like a bad idea. I still feel like I'm a little pressured to decide on something beforehand though, everyone seems to make it out as though this is something every student has figured out by senior year.