1: In what respect do they lack evidence?
In the 'lacking evidence' respect - you have partisan claims after the fact from limited sources with vested interests against a complete absence of any sort of corroboration from contemporary impartial sources. Coupled with that you have extraordinary claims that would leave measurable, detectable evidence which is not found.
2: There are categoric differences between, on the one hand Thor, Dreamtime and Allah and The teapot and unicorns on the other. I wonder if you can spot what these are.
The differences between them aren't really the point in comparison to the lack of any supporting evidence in favour. There MIGHT be categoric differences between them, but until we actually have some evidence for any of them, we can't determine anything about them in order to determine if there are any categoric differences. What there actually are, are categoric differences in the claims about them.
3: What are your grounds for discarding?
That which is asserted without any validation can be discarded on the same basis - you've failed to make a sufficient case for Thor, Allah, God, unicorns or Russell's teapot, I therefore don't need to make a case for discarding, you've not met a threshold for me to accept the notion in the first instance.
And what unfalsifiables would you not discard?
I'm not sure that anything is not open to question; I exist (though I can't demonstrate that to you) and beyond that everything is provisional - some things are, perhaps, a little less provisional than others, but that's as far as any of us can go.
O.