1. There will be a East Pakistan First Minister and a East Pakistani Assembly, but the FM can not overrule the PM. The EPA will deal with Bengali issues, and the PM will not intervene unless it is necessary.
2. There will be a Bengali National Guard, but not a separate military
3. Bengali parties will be allowed to participate in Pakistani elections, and Bengalis will still vote in Pakistani elections.
4. One currency for the whole country, but effective constitutional provisions should be introduced to stop the flight of capital from East to West Pakistan.
5. Bengali will become an official language of Pakistan, and will be taught in schools in West Pakistan. However, Urdu will be taught in schools in East Pakistan. New Constitutional provisions will be introduced to prevent attempts to suppress the Bengali language.
Will the Bengali leaders accept this?:
The issue is whether West Pakistan would accept devolution at all, which IOTL, is a flat 'no', with predictable consequences.
The best option would be for both Bengali and Urdu to be replaced as the lingua franca by another language (likely English), while allowing both languages to be taught throughout Pakistan (with either language set as the medium in either parts).
Devolution would end up with East Bengal declaring its independence, after its local assembly has no desire to get its hands wet in the various disputes of West Pakistan.
Why? In most of Pakistan, Urdu has worked pretty well as the lingua franca in a diverse nation. If Pakistan began to allow Bengali to be taught across Pakistan, it means other local languages, like Punjabi, Baluchi, Sindhi, and Pashto, will now have be taught across Pakistan. This breaks Pakistan's unity even further than Bengal vs. everything else.
Well darn. Is there any other way for Pakistan to hold on to Bangladesh? Maybe if Sheikh Mujeeb was made PM after the 1970 election instead of the government refusing to convene the parliament. Sheikh Mujeeb would most likely implement his six points, which would turn Pakistan into a confederation comprising of East and West Pakistan. Don't know what he would do beyond there.
However, I would not trust the military to know it's place. He would probably be couped by some Punjabi general, sparking the independence war.
No way, no how. It was simply unworkable and ludicrous to include East Bengal into Pakistan in the first place.
Not only is it geographically separated by a vast distance (i.e. all of India), but there are significant - and as we saw IOTL, insurmountable - ethnic, cultural, social, and linguistic differences between West Pakistanis (Punjabis, Pathans, Sindhis, Balochis, Kashmiris, and Urdu-speaking Mohajirs) and Muslim Bengalis. They are just too different and have no significant links, other than nominally sharing the same religion, and even then the type of Islam practiced by the majority of Muslim Bengalis is vastly different to that practiced by Pakistanis.
Also, in practice, West Pakistan treated East Bengal effectively like a colony, extracting surplus and giving very little in return (see the pathetic response to the 1965 cyclone, and various floods and famines). The West Pakistani establishment viewed Bengalis as racially and culturally inferior, refused to share power with them, tried to suppress the Bangla language and culture, and excluded them from most avenues of political, economic, and military authority, even though East Bengal had near population-parity with all of West Pakistan. When the Bengali Awami League party won the Pakistani national elections - and thus the right to govern all of Pakistan - the West Pakistani establishment and Pakistani Army responded with a military coup. That's how much they viewed Bengalis as inferior colonial subjects.
I'm going to requote an old post of mine on the subject.
Will the Bengali leaders accept this?:
Well darn. Is there any other way for Pakistan to hold on to Bangladesh? Maybe if Sheikh Mujeeb was made PM after the 1970 election instead of the government refusing to convene the parliament. Sheikh Mujeeb would most likely implement his six points, which would turn Pakistan into a confederation comprising of East and West Pakistan. Don't know what he would do beyond there.
If one wishes to keep them together, then one has to go back some considerable time. The behaviour of the Pakistan Army in East Pakistan (as it was at the time) towards the Bengalis was not good. By chance, I happened to be there, and witnessed what was happening on the ground, and the Pakistan Army basically lost all semblance of control, and applied a doctrine of subjugating the locals through fear and terror tactics, and indulged in unspeakable atrocities. By 1971, it is too late to change the attitudes, and the Bengalis were not viewed as fully human by the Pakistan Army.
I did say before that if Sheikh Mujeeb was made PM the Pakistani military, which had always been comprised of Punjabis, they would have been a coup.