Anon asked: What would happen if Ursa gave her children equal love instead of favoring Zuko? How different would Zucest be in this scenario?
That wouldn't magically fix everything, but would improve things a lot. Having someone who gave them both unconditional love and approval and that tried to preserve their sibling bond despite Ozai's manipulations would help their friendship survive through the years (instead of just the love and, later on, the lust).
That would mean there would be more trust between them, to the point that maybe their Agni Kai wouldn't happen and, possibly, Azula would leave with Zuko when he decides to join the Avatar.