I don't think Rose was tsundere at all. She's like a pure romantic who gave up on finding it and Itsuki just needed to reignite that part of her.love a tsundere. They never really got to the "dere" part for me, but a boy can still dream...
Didn't the goddess and sisters already find a way for Itsuki to communicate with his family? I'm positive this series will end with a big happy ending where it's very easy for him to go see his family and come back to the sisters.he'll obviously be able to change it. cause their main fear is that he takes one (or all) of them with him. and before the brainwashing he resolved himself to stay already. he just needs to be able to communicate this. and i doubt the author is shitty enough to not make this part of some future arc.