Well,Animorphs and anybody who has the morphing technology can speak telepathically with anyone, so giving consent wouldn't really be the problem. The problem is that it's still basically cheating at the Beastiality rule.
No, it's not. If Nemo can get away with Pokemon that have to communicate by scratching in the dirt, and if the furry stories can get away with ferals, you could get away with fully sentient, telepathic people with an animal's body.
Well, Pokemon and Feral Furries have the advantage of being able to claim Fictional creature. I do get where you're coming from though. Still...I think I have too many half-started stories right now to write yet another introductory chapter to a story i may never publish.