You've said a lot of things! I don't have the time or energy rn to reply to all of them, but about the Joseph thing - yes, his lineage should be irrelevant if he's not actually Jesus's father. I've seen excuses for why it matters, and I think the original reason is that the virgin thing was added on later, they originally did think he was his father.

And yeah, the virgin thing was the author of one of the gospels (I forget which) wanting to 'fulfil prophecy' with Jesus and reading something about how the Greek word meaning virgin or young woman would give birth to a son before something happened (in context something to do with a battle, like as a figure of speech to communicate a length of time). So yeah, it's about a normal pregnancy, and then it was interpreted as a 'virgin birth' which the gospel writer used to make Mary a virgin to 'fulfill prophecy' (which is in context nothing to do with the messiah).

I hope that's not too bumbling to make sense, in any case there are plenty people who've explained it much better than me, like the YouTuber Mindshift ;)

This is mostly about Christianity, which I will admit is mostly not my expertise. I will confirm that in the OT the Hebrew word does in context mean a young woman who has conceived a child in the usual way, however.