In reflection I think Michael WAS ready to be the Don. He was skitty and uneasy at the funeral, but thats to be understood. He'd just taken on the mantel of one of the most powerful jobs he'd ever have to take and he was looking for the 'traitor' which his father had told him would come, after his own demise. His thoughts and eyes were all over the place whilst all the while trying to grieve his dead father.
I've read some parts of these 'early scripts and first drafts ' and changed scenes and all, and good they are too, but wouldnt that alter everything, another world a different scenario...maybe...if it hadnt been altered? so are they still valid to be compared along with the famous story we now know and love? Just a thought