First of all, I cannot tell you how much I appreciate your opinion, and, honestly, I feel like your characterisations are just too good for me.
As to the citations mentioned, I would love to be able to send you all my grammar books (as an English teacher) and my other resources (as a Translation, English Language and Literature & currently MA student, and... student, in general) but most of them are hard copies, and it would require a lot of time, as well as copious work to do so (guilty as charged, I admit). All I can do is simply refer anyone to sites like this one
with regards to the 2nd conditional, and this one
with regards to the subjunctive mood, even though they certainly cannot be claimed to be highly reliable sources; yet, they do show "something", which is unboutedly better explained in the books I mentioned before.
Having delved into the wonders (wonders for me, at least) of the English language over the years, I have always been fascinated by the beauty of the subjunctive mood, since, as a student at first, I could just intuitively sense the "hi-story" behind it, and then as a teacher, I was able to see, or better read, the formal, grammatical "why's" behind it.
The explanation you so kindly offered to us is not only something that completely satisfies my curiosity as to why this mood is more prevailing in the American English than in the British English, but also something that no other book had been able to do so far! You just shed light on that, dark up until now, "pathway" of older structures into the English of today, and thank you for that!
I do have noticed how easily and rapidly language can be degenerated over the Internet, so I'm more than glad to be able to "set some things straight" as to the correct versus the predominant use of the language.
Finally, I would be filled with joy to "adorn" my views with the terms I'm getting familiarised with (such as "L1 interference", to name but a few), for anyone who is interested in that. I would actually be honoured to do so. :)