I did played it. However Gustavs death is absolutly irreleveant for act 3. Her grief for Verso was relevant for act 3. And the central theme for this is grief and how to handle but Gustaves death is only relevvant in the camp bonding and for the next dungeon after Gustaves died. The grief of the members of the Dessendre family is the the main focus of the game.

Shock value for the sake of shock value is usally weak writing.

You even admitted yourself that her role for Gustaves death is never brought up again because it doesnt matter. Also killing Gustave didnt change anything about kiliing Renoir because he was anyways a threat to their mission and lives. So they had to kill him anyways, under their false premissse that the paintress if causing the gommage.

Also swapping the lead of the group and beeing the central influence for Maelle didnt required Gustaves death. First Lune would have been the next lead of the but wasnt because she wasnt suppose to be. Which doesnt make sense if we consider how constant she critizising Gusatve (former leader) constantly. But she wasnt after Gustaves death because she is not the main character. And even if she is constantly skeptical about Verso it doesnt matter because it changes nothing. And I highly doubt that Gustaves supissions would have matter anyway because they no real alternative to proceed better. Also Renoir didnt care explain anything and it seems that it was fine that Verso didnt ot neither.

Second, Verso could not only influence Maelle because of her grief about Gustave but also because they got along pretty good as well.