I know all that and I actually agree with you about what 'overcoming' amounts to. No, doubt is NOT the original sin. Hubris is. Such as , the idea that our ideas (with, MAYBE, one exception) about what it means to 'be like God' are anywhere near the mark. Only God can so instruct us and in the clear prism for God's Light that is Jesus, He shows us the whole picture.

Doubt can be where we call on God for help to work it through. Again, working doubt through is essential; running from it doesn't help.

Faithfulness means always being humble enough to acknowledge that you haven’t fully figured everything out, being curious enough to evaluate new scholarship and arguments as they arise, and being honest enough to admit when you realize you’ve gotten something wrong. And when someone else does the hard work of walking this path, our mercy for them should be as wide as God’s for us all.