Lord Jim wrote:The point is, as far as I see it, is that " the language of the country in which you reside" is English....(or at least some barely recognizable facsimile there of... )
I'll leave that to Welsh residents to answer (RB?) - I currently live in England, so you are 100% correct that the language in which I personally reside is English

I wonder how you would define what the language of a particular country is ...
Lord Jim wrote:Do you think Latin American kids would be better served if they were required to spend 10 years mastering some obscure Aztec dialect as a part of their basic education?
Interesting question. I don't understand their education system - if it is as complete as (arguably) the British system is, and if their not learning it would usher Aztec towards extinction, then I would say yes, they should. Learning a second language would put them in a very strong position to take on a third, further down the line, and they would be able to travel to some parts of their own country and speak to their own countrymen in the only language that their countrymen can speak (which, if true, would verify your analogy).
If a man speaks in the forest and there are no women around to hear is he still wrong?