Ok, Ill bite...
It seems overwhelmingly self evident to me that people inherit their religious beliefs from their parents and the society around them. They don't wait until they're adults, capable of making these kinds of Big Decisions with a rational mind. They don't research all the alternatives and make an informed decision. They're basically brainwashed from birth.
I don't think this is completely true. You are correct, parents generally attempt to influence their children's religious beliefs at a young age, and religions provide means of education, indoctrination, and initiation of members from birth. I think brainwashing might not be the right word for this. However I also believe that as adults we all have the ability to learn, expand our minds, challenge the world around them, etc which usually leads to things like higher education and otherwise exploring different ideas about everything. I was raised Catholic, that is what I follow to this day, but not simply because that's what I was indoctrinated with as a child...as an adult I had questions, looked to challenge some of those ideas and challenging those ideas for me actually strengthened my faith.
If God really is a psychopath; i.e., if God really is going to send you to hell for eternity because you didn't believe or did believe, but believed in the wrong God, then the vast, vast majority of humanity is screwed, and is going to hell, because even if you do believe in the right God, chances are your faith and adherence to your religion is watered down enough to piss him off to send you to hell anyway...
Just one thing about the whole "right vs wrong God" thing...the major monotheistic religions (Christianity, Judaism, Islam - are there any others I can't think of? Maybe even Zoroasterism?) all worship the same God, even if some of the more fringe, radical types of people don't want to accept it. Just because a particular radical Muslim, for example, might believe that worshipping Allah is not the same thing as worshipping the Christian God, it doesn't mean they aren't doing it in reality. I might be able to stretch this a bit further by saying that maybe even some polytheistic religions are actually worshipping the same God I point to here, but they may simply incorrectly see other powerful spiritual beings as "gods". Catholicism gets a bad rap for this, some people seem to think that we worship angels and saints...this view is not correct. However maybe some of these polytheistic religions are looking at angels, saints, etc as "other gods". While God may not be man-made, religion is and therefore must be flawed in one or more aspects of each religion man creates. However the rest of what you say makes sense and surely is a possibility, except when you consider what you write next...
I would argue that to have true faith and confidence in God would mean having faith and confidence that he's competent and his plan doesn't suck so much that the vast majority of human souls will spend eternity in hell. You should have faith that God is not a complete psychopath just waiting to make the vast majority of his creation suffer torment for all eternity.
Now here is the big selling point for Christianity that seems to be lost on most people (including many Christians). Christianity is the new covenant between God and humanity. The concepts that are central to the Christian faith is this: God is perfect. God has created imperfect beings. God formed a new covenant with humanity and decided to be present among us in the form of a "human son" to teach us about this new covenant, about our imperfection, and eventually our salvation. The new covenant was sealed with the death of Christ on the cross, an event people commonly refer to as "Christ's personal sacrifice / death on the cross for our sins". The whole point of this exercise was for God to show us that he loves us so much that he sent his one and only son to "save" us from the devil, Hell, etc. (BTW: I really don't like the concept of the terms saved, salvation, etc, but since that is the common term I continue to use it.) He "saved" us by continuing to teach this path to salvation, even under threat of execution for these teachings. The path to salvation is based on our acceptance of our imperfections and the understanding that Jesus Christ is our savior, and that we should choose to follow the path to salvation through acceptance of the savior and therefore his teachings. However as humans we are imperfect - we can and do stray from this path. God knows this and as a forgiving, loving being/entity/bearded dude in the clouds/whatever forgives us for our imperfections, which we will never eliminate from our nature no matter how much we try. If we deny this covenant and therefore the teachings, path, etc then it is not God that damns us but ourselves. God does not send us to Hell out of hatred or disappointment, we choose to send ourselves there. If that's what we ultimately want, then God will provide it just as he as provided everything else in creation.
Incidentally for me, this is the pinnacle of what "free will" and "liberty" means. God is all powerful, but does not use that power to force us into anything. We always have a choice up until the moment we die. We are truly free only because the ultimate power that exists over everything chooses not to exercise a bit of that control over us.