I understand that Yurisha was sent to earth to deliver the construction plans for the wave motion engine and also Sasha to give them the wave motion power core but why did they do it separately? I mean Yurisha also could have delivered the plans together with the core...
The Gamilas empire expands and exterminates many other planets not only the earth. So why would Starsha want to help humanity? Moreover she and her 2 sisters are the only 3 remaining of her species. Also what would happen if the earth gets restored? The Gamilas just would have continued their attacks and bombs. If the Yamato didn't save the capital of Gamilas and killed their leader the earth would be still attacked sooner or later by the empire. But Starsha couldn't know that this would happen so her plan to help the humans and risk the lives of her sisters doesn't make much sense to me.
