Is the offical (English language) audio tour insightful?
Back in 2016 it wasn't very insightful. Googling provided far better information and more insights. I'd recommend skipping it.
Are there any renegade/unofficial alternatives to the official audio guide?
Google is your friend. Type in the name of the painting and you'll get dozens of pages with excellent overviews. You can also use ChatGPT to generate a personalized itinerary based on your personal preferences.
Does it result in a procession of headphoned zombies wandering in a congo line between the same exhibits?
Only the Mona Lisa and a few other painting rooms are particularly crowded. The rest of the museum has a lot of space.
Would it be better to get a paper/app/book guide and read that, then try to find the specific stuff that appealed?
Opinion based, we can't answer that. Just know that there's no wrong option. Visit whatever sections of the museum you think you might enjoy.
Is the official guided tour (human) a good investment of time/money?
Opinion based. Personally I think that Google is superior to group guides but some people might enjoy them more. If you can afford a private tour, I'd say it would be superior to Google though.
Are there unofficial human guides? Where to find/rate them?
You should ask a separate question about this.