Like I said before, I just can't really agree with your points as I don't really believe them to be what you think they are. Personal bias and all.
Minorin's avoiding of Ryuuji would be a prime example of your own declaration that japanese people are "
extremely non-confrontational, masters of passive-aggression and indirect communication" - it doesn't mean she doesn't like him because she's into
Taiga (it could, but I don't think it does. Again, personal bias). Same thing with her "
wonder if I'm a lesbian" quip - she's simply the type of person to come up with a "
joke" like that, when trying to diffuse a potentially serious conversation.
The speed of her shutting down Ryuuji's attempts to confess could also be attributed to any number of factors: not wanting to hurt him; not knowing her own feelings; being
afraid of her own feelings (
my pick), etc... Again, the whole perception thing.
Don't get me wrong, you're more than welcome to your own interpretation of stuff, I just do not agree with it.