Lets not poke into India's problems
A tall claim. Some sources would be helpful. India wasn't economically that strong compared to now. Also, they had a serious problem of refugees from East Pakistan.
If you are a supporter of an independent Bangladesh, how on earth would the Mukti Bahini fight alone? One can't fight a professional military with WWII era rifles, grenades, and some basic training. They were no match. I know the Indians did conduct Special Forces and intelligence operations at the time in East Pakistan, but that is a different story, and it was one hell of a well conducted operation.
You are right about the AL looting part. That is a fact.
Bengal always had some level of poverty. Even during the British era. You have to look back as to why the All India Muslim League was created in the first place. Most of Bengal's aristocrats were Hindus, Muslims simply didn't want to integrate with Western knowledge and know how. And yes, there was some discrimination. Generally speaking, Bengali Muslims had little or no education, and that problem still runs high today.
Have we progressed as individuals and generations throughout the years until now? Yes. Our generations have come very far. The Liberation War did help us in that path to go faster. But the question is, why is Bangladesh still poor? I think you know the answers.
The IAF at the time of the Liberation War wasn't as...awesome as the PAF, but it's Eastern front had a very weakly defended airspace. The PAF was pretty much owned there. With Pakistan losing both air and naval advantages in the Eastern front, their army were just holed up in face of the upcoming Indian blitzkrieg. The result wasn't pretty for the Pakistanis, and surrendered to IA in the end. You see, it wasn't only a military success, it was a covert, some propaganda and political success. It was a brilliantly planned strategy from the Indians. West Pakistani arrogance only strengthened the Indian strategy. What can I say, beautiful, just beautiful!
It isn't only because of India that is the root cause of our problems. India just reaps whatever benefits they see. There is no such thing as 'quality control' in Indian politics. This similarly applies to Bangladesh.
As far as the transit deal goes, I think it is feasible in the long term provided that political football in Bangladesh doesn't hinder the benefits. It has pros and cons.