That's awesome! But one question, couldn't the kindle book editions differ across countries in some cases? Just as, as for example, physical editions may differ between America and the UK?
There may be differences in some cases, but usually western versions of print books tend to be better (color illustrations/pictures, etc.) to justify a higher price. That distinction doesn't really apply to digital books so for the most part, they're the same. (unless there are censorship/localization issues)
I'm from India, and I use the American Kindle store as many books I want to buy are not even available in the Indian store. I haven't checked for a few months though, so things may have improved.
You can switch between them as and when you like. Every book I wanted so far was available on the Indian store. But if the book you want isn't there, you can switch your Kindle region and buy that. Then, later, when you want to get one that is available on the Indian store, you can switch back and get that at a cheaper price!