No, I don't think it's being closed minded. I always respect the opinions of people who have thought things through, whichever conclusion they have come to.
I think you can change your mind throughout life. I've never been an atheist - at best an agnostic tending towards belief (or as you would put it being swayed by wanting to believe!)
Well, we all have our preconceptions, regardless of our point of view - it's part of the human condition. As long as we try to be open and honest with ourselves as well as with others, I think we're moving in the right direction.