There is something to be said about Aziraphale potentially thinking Crowley is manipulative because of his role as a demon in Temptations. Crowley *did* tempt him into food, at the very least, and *has* lied to him.
I'll also point out that therapists are human too and therefore not always right, make mistakes and misdiagnose (and by extension mistreat) more frequently than they should. (Obviously in a perfect world the frequency should be never, but that's not the world we live in)
That being said, I also don't think Crowley is any more manipulative than most people on this planet. In a way most if not all that we do and say can be argued (in my cynical world view) to be self-beneficial and often persuasive/manipulative. There's always something in it for ourselves, even if it's just a feeling of self-sacrifice, which in turn creates this notion of righteousness.
I don't see Crowley acting out a more amplified version of that. (Nor does Aziraphale, to nip that right in the bud.) Within his capacities as a supernatural, (potentially?? If erasure from existence is a thing???) immortal being, whose limits, limitations and stakes are simply far beyond our own, he acts very human... I don't wanna say "almost humble even" bc honestly he's too balanced for that, in my opinion.
In terms of naivety... idk. Maybe it's a language barrier thing and/or my understanding of naivety encompasses much more than ☝🏻yours. I never viewed naivety as an inherently bad, wrong or laughable thing like many people seem to. To me the trust in goodness (and good intent) is something beautiful and, at times, enviable. Despite my cynicism, I, too, hold on to my naivety (which isn't to be confused with autistic face-value-understanding, but does influence it in my case). I think it's a good thing. Again, maybe my understanding of naivety is biased and incorrect. Maybe it has slightly different connotations in English than it does in German. Maybe I'm just a dingus. I guess just don't like harsh lines to be drawn on most things. Living in that gray area.
They're flawed, as round characters should be, but not 'intentionally harming you're kind of flawed.
So... yeah... I could see Az getting the idea that perhaps he was/is being manipulated by Crowley now and then, and even in the Final 15, but I would think he brushes off that possibility as quickly as we should 🤷🏻♂️