That is where your problem is. You don't have any choice other than Sheikh Hasina. The Next Options are Begum Zia and Jamat e islam. If Sheikh Hasina demands something, Delhi will obviously want to give it like they gave lands and sea before.
Incorrect.
There is a second generation of leaders that India has cultivated in both parties - AL as well as BNP. The plan is for decades ahead. Those who will take over BNP after Zia passes away.
The reason why India honors Sheikh Hasina much more than others is multifold.
1. Sheikh Hasina has a direct, I might add emotional, connect with all the powers that matter in India (both Congress and BJP). She resided in India for a long time as State guest.
Just like Syu Ki. Our President calls Syu Ki his daughter.
She has the ability therefore to get her request honored directly, bypassing all bureaucracy. And most leaders are emotionally invested in her.
2. Sh. Hasina has been not just neutral towards Indian security but proactively positive towards it. She has gone the extra mile each time to ensure India's security.
Indian Govt. of any party that in return by going the extra mile on Bangladesh's requests.
3. India wants a gigantic economic zone connecting East India, North East India, Myanmar, BD and Thailand. The first step towards making such an economic zone is ensuring that all the States concerned have territorial safety from each other - that means all countries must resolve their territorial disputes. Under that ambition, India supported not just resolution of India-BD territorial (land/sea) disputes but also Myanmar-BD ones.
The expected gains here are in hundreds of billions of dollars.
As you can see, the premise behind India-BD cooperation has not been a threat of Bangladesh to harm India's security. That means nothing to us. We can ensure harm of Bangladesh's security ten times more.
It has not even been Bangladesh being neutral/passive on India's security. The premise has been that BD as a neighbour went the extra mile to ensure Indian security. GoI thus has to go the extra mile on Bangladeshi concerns.