Re: Faux AZERTY
" I would love it if I could set the keyboard layout independently i.e. without having all the Microsoft apps changing language."
Not entirely sure what you mean here - in my experience Windows allows you (and has for many years) to have multiple keyboard layouts for whatever languages you have installed, separate from the Display language. For any given installed language, you can pick a default keyboard layout and also switch between which ever ones you have configured for that language on the fly.
I used to have a similar setup, only in my case the laptop keyboard was German QWERTZ and my external wireless was UK QWERTY, and the system was installed in English. I was easily able to switch to the German layout when I was travelling using the language picker in the system tray, without affecting any display/app language.
Additionally, most of the MS apps have application specific language options. I had to find these earlier this year when I was switching my new (corporate German install image) laptop to use English as a display language, albeit with a German keyboard....
The only annoying thing for me right now is that the proofing tools don't detect what language I'm writing in, they just use whatever I had it set to last.