I stuck with it and found some gems but it comes across as a nasty case of naval gazing (similar to the navel version but you have to spit out the bits of rope stuck in your teeth, or choke)

The initial paras are quite fun parodies and explained soon after.

"English, unlike French, has no academy to protect its virtue": thank goodness - English has no virtue and no morals. It takes what it needs and returns the favour in flexibility. However, English spoken by a French person does sound rather lovely.

"guerrilla outfits of Berks and Wankers" - I've never read Amis but it seems I might have to:

"Berks ... Left to them the English language would die of impurity, like late Latin."

"Wankers ... Left to them the language would die of purity, like medieval Latin."

I too was educated at a posh prep. school (but in Devon, UK) and a posh public school in Oxon (public schools in the UK are private schools - we are a bit odd). I too was taught "correct" use of the language, except that I was taught en_GB rather than en_US. I still have my copy of "Use and abuse of the English language" somewhere. I should probably recycle its materials.

English does not require an Academy of Immortals to look after it. There are a few good reasons why it is a good first and second choice for a Frankish Language, one of which is that you can use and abuse it and still be understood.