I personally have the trends country set to one that doesn't usually have a very big (or any) presence on Twitter (e.g. British Indian Ocean Territory, Falkland Islands, ...). This makes the "Trends for you" part of the page empty.
That's amazing. I picked the country Chad and I see no trends at all! With word and account blocking, I get good control over what I see, even in the official Twitter app. (A good number of the control methods, like disabling like numbers, are only available via browser extension.)
No, that's not how it works. The only way it would start getting content is if users actually started tweeting from those remote locations, which seems unlikely.