I think she gets featured enough in Heaven's Feel to understand her as a character, at least. Of course, compared to the heroine boost she enjoys in...
Considering Mahoyo implies that Soujirou and Eiri come from a similar/the same background I could absolutely see it being expanded in some way shape...
I heard about Melty Blood and thought it looked cool, so I did some research on it, and decided to play the original Tsukihime. Fell in love with it,...
This part was already answered in 1's epilogue. Soujuurou asked once why his mountain's traditions were like that. That's not a thing he was supposed...