Hi LovelyBear-
Maybe someone will touch on all points you’ve brought up but I want to touch on just a few that I feel I can answer.
As far as getting your dogs teeth healthy, nothing can replace brushing your dogs teeth and dentals at the vet. No, they are not simply trying to sucker you for money. Having your dogs teeth cleaned at the vet is just the same as us having our teeth cleaned at the dentist. Between that and brushing is the most effective way to get any bacteria and gunk underneath the gumline. Bones and chews will clean the crowns (what you see), but will not necessarily prevent periodontal disease.
There are a lot of vegans on this site who still understand that meat is a part of a dogs diet. There is no shame in that.
