They did ascend to become the gods, but they built the machines before they became gods. Which means they didn't need the extra power divinity gave them to make the refined wheel process. Which is what is important to the question of whether these soul amalgamations are actually gods or not.
I thought we were only talking about faults and responsibilities. I was just saying that, due to the ascensions, the souls that became gods are responsible for the "breaking" of the natural wheel.
The question of whether these souls amalgamations are actually gods or not is even more pointless though, because to answer that first you have to define what a god is and the definition itself instantly answers the question. If by "god" you mean the Christian god creator of the universe, of course they are not. But if you mean the generic fantasy concept of gods, they are instantly gods simply because they act as such and there are cults devoted to them. In PoE they are gods because people call them gods, the end.
The fact that
"nothing technically depends on their existence" means nothing, when did that become a requirement for something to be a god? What natural phenomenon depends on Bhaal in the Forgotten Realms? The universe existed before him and definitely kept existing after him, and yet he was a god.
As for your second argument, you'd have to expand on that before I can find an answer because I can't really understand what you mean. Since the Engwithans ascended, nobody willingly gave the gods any power. Everyone on Eora can suddenly decide to stop worshipping them and their power wouldn't change one bit. Kiths don't give them any power, they take it because the source of their godly power (the machines) allows them to. They can end all life on Eora in the blink of an eye whether anyone worships them or not.