I voted yes for everything except "no divine classes at all", and I'd even be willing to give that a go if I thought the DM had a cool concept effectively worked out. The only reason I'd be hesitant is that I think the functionality of the cleric and related classes is a part of what makes D&D work as a system; taking it out means a serious overhaul, and it becomes less like D&D and more like a homebrew game system. I have no problem with the functionality of the cleric class being given a non-divine rationale in a D&D game, however.
I consider most of your suggestions to be improvements. One of the things I have always found irritating about D&D is the way PC races and monsters of every conceivable type are just tossed into the world in a jumbled heap, with no sense of coherent underlying world concept. As a DM, I tend to design worlds that are more low-fantasy, focused in on a few key PC races and monster types. I like unusual creatures to seem truly unusual.
I sometimes think that the mindboggling randomness of most D&D worlds evolved because the original rulebooks just pulled together everything that anybody had ever used in a campaign, and so new players reading the books just assumed if it was in there, they needed to use it.
I always give my worlds a narrower thematic focus.