Even if your position is correct, which it seems to be, what difference does it make? How are you defining virginity? Do you mean Joseph never had sex with Mary after the birth of Jesus? Hard to believe and why would it matter that he did? I think this is the point you start to vere off into “Mary worship”.
You made a good point about the people mentioned as not being siblings of Jesus. This still doesn't mean he didn't have any other siblings. Also it doesn't really prove your idea of “The Perpetual Virginity of Mary”. You only addressed some claims against the idea.
If I claim that the temperature in hell is 99 degrees, just because you can't “prove” I'm wrong, doesn't make me right.
**Even if your position is correct, which it seems to be, what difference does it make? How are you defining virginity?**
You need to read the last paragraph above. What did Luther, Calvin, Zwingli say about it. LOL! Check it out with them.