lil red dude is so cute and chunky (yes im adopting him)
This is some good work and thought about how fluffies would be - I can’t find anything unreasonable or illogical other than some personal design preferences (I’d have gone for herbivore teeth myself, since you’ve given them a hindgut).
These are a fucked up mess of an animal on par with pugs - perfect fluffies in other words. 
Hell yeah! New Ambi posts with medical diagrams for the intestines and skeleton. Super cool, I miss your fluffys.
It’s technically a single stomach, not a chambered stomach like an herbivore. But there are two distinct lobes. I imagine a bit like a bicornuate uterus, with varying degrees of divide.
I was looking at everything like “what’s the most inefficient way this would work?” Omnivore teeth from pigs, but a weak horse-style gut that relies on fermentation and bacteria.
It would also mean that fluffy shit and fluffy corpses are just loaded with pathogens. They were designed to only live indoors and away from other animals, so they are extremely susceptible to disease. Decomposing fluffy corpses would easily explode if the gas wasn’t released.
Hippo feet. The three toes means that the fore-hoof would be leathery and flexible for holding things. I imagine like trying to do anything with your first three fingers inside a thick sock.
But! They do have very flexible horse muzzles, and can use their mouths to do things, but at the expense of their delicate omnivore teeth.
Also I feel the skeketon deserves more attention. There is a lot of comparative anatomy. I took a perfectly good shetland pony skeleton and made it awful.
Yeah, I agree; with that digestive system setup you’ve gone for, there’s anaerobic bacteria a-go-go, so lots of gas from both ends, incredibly bad smell and lots of gram-negative pathogenic nastiness.
I live in a semi-rural area and when the farmer goes mucking, we can smell it over a mile away if the wind’s blowing in the wrong direction. I can imagine how bad it’d be to having that directly sprayed on you via sorry poopies, especially if you’re not used to it.
All your other design choices make perfect sense within the scope of designing a fluffy and shipping the minimum viable product; go with whatever works, rather than whatever’s optimal.
I can’t comment on your skeleton - that sort of biology is outside my wheelhouse, but it makes sense to me to make a perfectly functioning skeleton and make it less perfect.
I think due to the smaller mass than a Shetland pony, the fluffy doesn’t suffer as much as it should (less strain on the skeleton), so it can be crappy but still vaguely function, rather than collapse under the strain of its own bodyweight.
I do like your solution for how fluffies can hold things with their forehooves; my wife’s dog does similar with long stick-shaped treats (hold them with his front paws so he can chew them, but toes that work like half-arsed fingers sound perfect to me.
i dont understand this leter