Religion as you have acknowledged is more than merely intellectual assent.
No, not more than, something entirely separate from intellectual assent. Religion is not an intellectual enterprise, although there's a great deal of intellectual enterprise after the fact trying to justify it.
It is a warm feeling caused by some aspect
So are sex, if you're doing it right, and (so I've heard) heroin.
A godless universe is an intellectual construct and Goddodging the preserve of those conscious of their own sin.
No, the universe is. An understanding of it as a godless existence is an intellectual enterprise; 'god-dodging' is an attempt to shift the burden of proof, again. You want to claim 'god' you need to establish 'god' or go claiming it to people who are prepared to expend their intellectual energy after the fact trying to justify the unwarranted conclusion they've already come to.
Any explanation for how an atheist concludes atheism yet?
Yeah. There is a world. You claim there's an unseen force behind it, and I say 'prove it'. You fail, I therefore remain an atheist until, and unless, someone comes along with data that results in new information.
Or how irreligion is the default position.
I'm born. I don't know about religion, therefore I'm irreligious. I then go to school and the majority religion in my area tries to inculcate me with their religious belief... I started out without religion, though, and therefore the default is irreligion.
This isn't really rocket surgery...
O.