I'm not picking on him. I won't persist. I'm just not talking about story anymore with him, when part of my complaints about this game is how badly implemented the Inquisitor origins can be. Some better than others (even human to an extent). To me, it's the big pink elephant in the room.
I'm going to be stubborn about it. So.. as much as I like you, I'll risk the Sith asskicking. 
Yes, that's fine. You can criticize his basic notion or refuse to discuss something blah blah. I do not even disagree regarding the origin stories (which, I think, don't actually exist). But I don't like that patronizing BS about avatar and age. I believe you're better than that and I want to go on liking you. 
The Inquisition was needed to bring order back to Thedas, sure it was originally intended to end the Mage/Templar conflict if the peace summit failed but considering the Breach and Cory it became needed for another reason
Like a monkey wrench. But does that explanation satisfy you? Some ominous "They wanted to restore order"? I find that a very vague description. They obviously did not have any plan. If they had, who would stop them from following it despite Corypheus' presence? I am running errands all the time, collecting shards, hunting ram; I am fairly surprised that I am not escorting tourists through the wilderness. So how come I did not have a bit of free time to dedicate to the original problems?
Now I'm wondering exactly what the inquisition was going to do pre-Breach/Cory. I mean if the Mage/Templar didn't listen to the Divine, what power did a group of people calling themselves the inquisition was going to do to the Templar/Mages?
That's my point, basically. It feels half-baked to me. In the beginning, the Inquisition suffers severe problems to gain support. "We need more allies, show them that only you have the mark to seal the breaches!", later "We need more allies, show them that only you can defeat Corypheus!" So what would they have done without the breaches and Corypheus and the mark? What was their plan? Because they had a fairly organized structure already when I was brought to Haven.