Ok, my turn ji lol.
I think Baby is the worst choice possible. She is too short tempered, she needs it her way or its's the high way ji. This is one of the reasons I dislike Baby. Anywayz, to be diplomatic here, Baby will be married off soon, and she needs to handle her life rather than Krishna Villa's.
For me at the moment, there is no one that can take Baa's role b/c Baa is Baa ji. I mean Motabhai is out of the running b/c he is too dependent on Baa, and we saw how he reacted to Baa's hospitalization. Leela is good person, she has taken care of the family as if they were her kids, even more than her own kids. However, she lacks the power within herself ji. I mean she is too eazily taken into words, and she doesn't have the stance in her like Baa. Leela won't be able to handle the bigger issues.
Then Praveen, who all might think is a bad choice, but maybe he isn't ji. Agreed, he's very greedy in money matters, but he loves his family dearly ji. When Praveena died, he showed great potential for someone who can lead his family. Although, yaading the episodes of the fight, he was very 'narrow' there ji. Anywayz, if there will be a choice na, Praveen would last in the choice, not in the family.
Then Meenakshi is a big NO right now ji. I yaad her in those fight wale episodes, when Motabhai told her to buck up. She tried, but it really didn't happen. She is a very strong person, and she stands up for her family. But the thing with her is that she is naive dil se, she has a pure heart ji. Anyone can come and take advantage of her kindness. The utharadkhikari should be koi who is strong like Baa in matters that some people may blindly fall in.
Subodh and Hemal are a no b/c they are too nice lol. I just don't see them being able to control the family like Baa.
Shilpa and Gudiya, haye ji. Shilpa is a no, b/c she puts science in everything, and she thinks too broadly for the whole family. It's great, but then when you have a family of different variety, that thinking doesn't go well ji. Baa can understand and respect Meenakshi's view, and at the same time give full respect to Shilpa's view. However, with Shilpa, it's alwayz been a view that only heads in one direction. Now, lets tackle Gudiya lol. If she actually acts a bit smarter, and follows Baa's laid out rules of most things that are for the good of the family, she may pull it off ji. I mean she has the potential in her, it's just how she carries it.
Harshad may be the best choice right now ji. He thinks practically, but he has Baa's laid out beliefs in him too ji. He is ready to believe in things that science or education don't explain(unlike Shilpa in many situations). I think he may pull it off ji.
If everything else fails,Gattu hai! He may turn out to be right person for the job!
Now, after my rant at past 3am, I must go ninni! Sorry for the long rant, not even sure if I made any sense ji.