To anyone doubting what Zaros has said to us firsthand, please pay attention to what he says in his memoriam device, which is practically his diary. This was the first thing I did in Fate of the Gods, collecting his crystals and checking it out. From what I gather, he wanted to escape Freneskae and explore the universe, which is quite similar to how a mortal child may want to go out into the world and sate their curiosity.
As for his alignment to order and control, let's take a look at how he describes demons, the first mortals he ever met.
"From the Chthonian dukes to the Avernic slaves, each individual a cog in the machine. Even the ousted Infernals have a part to play."
I believe that while he tries to control people (or at least used to), it was to allow them to grow and uplift themselves. And let's also take a look at how the vampyres had changed since Zaros met them, and showed them culture and society. Before then, they used to run about in the wild and squabble over prey.
"Unified, they could perhaps cease their infighting and become greater than the beasts they are."
Then we have the Mahjarrat. As Zaros says in the memoriam device:
"Within the empire they will rule as princes, and they shall be its inheritors."
He then goes on to say that they took over from the Chthonians after he left for Iaia and Freneskae, the empire sustained itself, and his presence wasn't needed (meaning the Zarosians were completely willing to follow him and were not controlled). And now he intends to make a mortal form strong enough to save us from the revision.