You're the one lumping all theistic religions together in the first place

Talking about how
theism is the main cause of violence and that it's eradication or reduction would lead to increased peace throughout the world. What a load of BS.
You have a knack for constructing straw men. Quote the statement I made where I said theism is the main cause of ANYTHING.
The point that I've been making all along is that theism makes it very easy to oppress people, not that it is the sole source of every means of oppression in history. Perhaps I should specify that Abrahamic monotheism in particular has a trend of doing this, but it really can apply to any religion that worships one God and has clergy that claim to speak for him. It's just that the less dogmatic a religion is, the less likely you are to have all of this oppression happening. Polytheism can be used for means of oppression as well, but it's not quite as successful at it because gods tend to be like people and bicker amongst each other, or at least their oracles and priests/priestesses do.
Religion means a set of belief systems that relate to spirituality. You can't just cherry pick what you think are the bad/violent religions or just think that all theistic religions are violent. That is asinine and is nothing more than ill thought opinion. Religion doesn't make the person, the person makes the person. It's the same dumb argument that guns kill people...it's stupid. So, lets take away all guns and that means that violence would decrease!
I really already addressed this in a previous post. Saying that the world would be more peaceful if there were more non-theists is not the same as saying, "All (theistic) religions are _____." I will say that trying to claim that the responsibility falls solely on the people is a cop out that's akin to saying that you can't blame Fascism for the purging of all opposition in Fascist states, but can only blame those people who actively carried out the murders. THAT is an ill thought opinion. No religion, no philosophy, no political movement is above criticism, nor are the crimes perpetrated by its followers above rebuke. If the political movement says that its opponents are responsible for all the ills of the world and need to be wiped from the earth, and then its adherents put that into practice, then it deserves BLAME. If Christianity says to kill witches, to kill men who sleep with men, etc., and the believers do that, then it deserves BLAME. If we can look at the practices of tribal religions that have practiced cannibalism and human sacrifice and consider them barbaric, then the same should apply to the violent practices of supposedly more civilized religions as well.
The world would not be a peaceful Utopia if we were all Janists or atheists.
Has anyone actually asserted that that would be the case?
There's a big difference between saying there would probably be less problems and saying that there would be no problems at all.
Man destroys religion. In fact, Janism has been used as a tool for greed. The first emperor of India was a Jain and yeah well he defeated many Kings and even Alexander the Great's General. Yet Janism is highly touted as peaceful and non violent. All religions are corrupt-able by man. If religion didn't exist then man would simply use another guise.
Well, I can agree that all religions are corruptible, but some are much more easily corrupted than others. You'd be hard pressed to convince a practitioner of Zen Buddhism that the Buddha wants him/her to kill someone when one of the most famous sayings from Zen is, "If you meet the Buddha on the road, kill him." That's actually an anti-dogmatic approach. However, if there's one god, and he's a living god, and you can convince people that you're a direct spokesperson for him, that makes it very easy to bend people to your will and can end up with anything from fleecing people of their money, to burning people alive, to things like the Jim Jones and Branch Davidian incidents. Now, if we're talking about DEISM, that's a little different because that's a situation where the god/goddess has created the world/universe and then pretty much abandoned it. There's not really any harm that can be found in that concept because the deity isn't there to push people around or use them as mouthpieces.
I must also say that if someone wants to kill gay people because their
holy book says so, I don't think that's a corruption. If it didn't say anything at all about doing such a thing and they still wanted to try to say "God said to do this," then there would be a case for corruption taking place, but it is actually there in the scripture. If you want to say that that's taking things too far, then the zealot priest or preacher can reply (as these types often do), that the Lord says, "since you are like lukewarm water, neither hot nor cold, I will spit you out of my mouth!" We can look at your example and say, "Well, this guy was a bad Jain, but that doesn't necessarily mean that Jainism is bad," but what about the Christian and Muslim murders of various outcasts that have gone on for centuries because it's commanded by their holy scripture? What about the human sacrifices carried out by the Aztecs because it was essential to their religion? What about the Thuggee murder-worship of Kali? None of that is "destroying" the religion, those are events carried out because the god or goddess supposedly commanded the followers to do such things.
By the way, even though I humored your argument, Chandragupta Maurya actually didn't become a Jain until towards the end of his life; he abdicated his throne immediately following his conversion in order to become an ascetic, so his days of conquest and wealth were far behind him by that point.