Such a fantastically thorough analysis! Covered everything! It's a lot to think about let alone pen it down but thanks for doing it: I've been thinking about it from every angle that right now, it's too muddled up to articulate.
Reading your analysis, I felt that we are faced with the trolley problem, with a twist. Ek rail ki patri par puri family:RJVs and Mahs; dusri patri par Mishti. Train driver hai Meenu but she has no conscience. And Abir will have to become Spiderman and weave his own web around Meenu and the train to stop them. But how?
And if Abir doesn't? Firstly blame the writers/TRPs and secondly, give up all expectations and quietly watch the show out of loyalty. Feel like if Mishti leaves with her dignity intact, might as well take the cue and do just that.