Can you purchase Nintendo Switch games from multiple regions and access them from the home screen as if they were purchased in the same region or is there a catch?

Yes, import away. If you're buying through the eShop, I'd recommend setting up a 2nd account for the target region. Changing regions on one account is disabled when you have a balance and would require calling customer service to delete any remaining change.

I'm trying to wrap my head around this... didn't know you can even delete digital currency in this sense. 

 

Even if you have a remaining balance in one currency for a specific eShop, any profile on the Switch can play any physical or already-downloaded game.

But seriously, just make a 2nd account to access another eShop. That way you can carry multiple balances at a time.

So I could have Japanese e-shop games on a US system with minimal hassle?    WHY DO I NOT ALREADY OWN ONE OF THESE

 

You can also download jpn demos too, which is super cool