Here's what Lennon said about the song:
"It is the concept of positive prayer. If you want to get a car, get the car keys. Get it? 'Imagine' is saying that. If you can imagine a world at peace, with no denominations of religion--not without religion but without the my-God-is-bigger-than-your-God thing--then it can be true."
I think it's a great song. And, I liked Neil Young's cover of it--crazy-lookin' ol' Neil still has a voice that harmonizes with itself.
Great research! I tried searching for that myself, but had no luck. I see nothing wrong with that. Straight from the songwriter himself. Lennon is probably rolling in his grave, seeing how other people are attempting to interpret his writings and as you showed, they had it all wrong this whole time. Oh well......
Only a person also on hallucinogens could understand this explanation.