I'm sorry but none of what you are describing is abuse - not what most people advise on the forums, sure, but abuse? Nope. *shrug*
As absolutes ("you must" do this or "you must" do that) I don't think anyone here would agree with most of the comments you've posted but there are always exceptions to every "rule" - chinchillas don't read the rule books.
If a cage is big enough then no shelves won't hurt (although we know chins do like to jump so shelves and ledges are enjoyed by chins) as long as the chin can bounce about with enough space - we wouldn't recommend no ledges though.
Wire bottomed cages - in the UK that's what most chinchilla owners use & again, we use shelves, platforms etc so the chin isn't on wire 24/7.
Dust baths left in cages - I've got some (mainly rescue) chins who have dust baths in their cages with no problems what-so-ever. No dry skin, no peeing in the dust, they can bathe when they want and sit in there to sleep if they want ...... what's the problem?
I actually think some of the YouTube videos from self-titled, supposed 'chinchilla experts" are often more dangerous & filled with inaccuracies than some of the 'pet' videos I've seen. I've seen people advocate all sorts of nonsense we'd never recommend on the forums.
Most of the accurate, correct information, even when given by properly experienced chinchilla owners/breeders, gets ignored or the OP and their supporters post abusive replies which I find very sad.
Sometimes you just can't fix stupid.
Honestly, for the sake of your blood pressure, I'd steer clear of YouTube for a while.