It’s not that there are Orcs, but what kind of Orcs they are that’s important. In terms of role, Orcs so far have been shown be closer to Warhammer Orcs, rather than Warcraft Orcs. The former is a scourge, the later is a hostile nation. Same goes for Werewolves, who from what we’ve seen so far are predators who’ve lost their humanity, and Necromancers, who raise the dead to terrorise the living. They would need to add more ambiguity to their aesthetic for them to be believable as recruits, because right now they look like monsters, act like monsters and are described as monsters. The only plausible result of having them in your company would be for everyone to get killed if you ever enter a city, not to mention the effort involved in making them a viable part of the game. Like how Orc armour doesn’t drop currently because humans cannot wear it. You’d have to implement all that armour if Orcs became recruits. Most importantly however, these changes would mean that you’d be also throwing away the old folklore feeling of humanity dealing with the threats of the world and trade it in for the standard D&D flavour.
Half-Orcs also always stand out in fantasy as blatantly not making sense as a race, though explaining why would get squicky. It’s a mimicking of the whole Uruk-hai deal without looking at the role that Saruman played.
We want to keep things down to low power fantasy and promote a certain asymmetry between the player and the opponents in the game; Battle Brothers will always be common humans in a pseudo-medieval setting that sometimes have to go up against non-human and supernatural foes. For this reason, your first three points are never going to happen. This isn’t a balancing issue at core but a design decision on how we want the game to feel. However, wardogs are a planned feature for both the player and the bandit faction. Other animals may or may not be added as well.
Sounds interesting. I’m guessing dogs won’t have levels like humans, but will have to indirectly be improved through a mercenary or a special companion (if upgradeable at all). Probably faster than humans, but less well armoured. Possibly useful for pinning down fast enemies and those that are fleeing.