I think this change can be made from little things. For example, keep the conflict between Elena and the protagonist be find a reason the latter is TRULY responsible for to make Elena refuse the recommandation to him. Keep the aggressive and wild mother, still doing her rebellious things, up to the point she is truly confronted to true despair and has no choice but to surrender to the aunt - in a light and comedic manner.
It is made of so little things that can be resolved from dialogues first.
I disagree, those characters as are in premium are not rescuable as is nor can be turned around without loads of problems (it is almost impossible to change first impression of characters in a game that is developed over months), nor is MC himself. Alice has become a weakness instead of a strength as Cinderella in distress and it is the main overarching story of the game as is it seems.
They will all need an overhaul from start, given better reasons for their actions and become more relatable and have something to love about them and same for Sofia and dimmed down by a lot. Aunt you might save maybe with adding more to her and Zach can be dropped reasonably easily if dev wanted it, but it would have huge consequences for story and planned conflicts.
Basically the dev has three options at the moment:
Continue premium as is, maybe try to salvage a few characters later in game by succeeding in turning them around and make them loveable despite first impression and people wanting a relation with them. This will be hard and will require some great writing and will likely conflict with currently planned things in game, since they are likely as they are now for a reason. Likely you will lose players like me, but you might keep players that like consequences and lot of antagonists on board and get new players over time.
Redo the premium from start, maybe even as a fully new game with new characters and story from start that will be less overblown. Disadvantage it will be a rework on a rework and dev must be behind that idea in the first place and have ideas for that. In my eyes probably in long run best option based on my opinion of the premium, but it is not like my opinion is law or the TRUTH.
Last option, go back in old game to before the reintroduction of Alice and use that to introduce characters like the aunt with drama that is more based on conflicting viewpoints or inability to communicate while they still care for each other and add the story and drama slowly from there. Disadvantage you miss the whole Alice arc as such and will need to be changed to fit new drama, overarching story arc needs to be changed into for example the reconciliation between the sisters and let aunt and granny agree/to convert to your life style as MC.
Disadvantages same as two, going back to old version, needs a technical rework to add the improvements from premium which will take loads of time and it will be hard to introduce extra drama for the old characters since they are already set in stone like MC, so you cannot make him change and grow too much, which is also the single real advantage since that will keep the tone lighter as many liked.