Update idea act two town toggle switch. Like I know the whole thing with the lasypt quest is that it won't be the same afterwards but I still feel like a toggle would be a good idea you could have it as a laptop thing as well.
No.
Making the player able to go from act 3 into act 2 would be a massive headache, specially if they want to go back into act 3 later.
Just keep a save on act 2.