Weird... I have a UK Nintendo account linked to my German PayPal account that is linked to my Deutsche Bank account. I buy UK digital games all the time, no problem.
Sony splintered all the regions into different stores due to legality reasons (different rating for different games in different regions, etc)..
Microsoft essentially 'workaround' this issue because the Xbox ID is your microsoft ID as well for outlook.com and their cloud stuff. MS is kinda lucky that no government come to knock on their door on this.
Nintendo's i think is just a hole that they haven't plugged yet. Their nintendo network system is still in its infancy that i don't think they know to to region split their store properly (Google Play Store used to be 'region-free' too in its infancy (you can trick it via vpn or by using an app) until Google plugged this hole).
Nope not at all, which is a bit of a problem. I get that it's a relatively small market, though given how many of the kids I teach have PS4s, it's a growing one. Because the US dollar is one of the main currencies here it'd be no problem (logically) to just add it to NA I would think, but maybe it's more effort than it's worth?
We can use other European Switch eShops just fine with our cards (even South Africa for some reason) if we're already in Europe, just not the American and Asian eShops.