Everyone else even Roth believed Batista -- we will tolerate no guerrillas in casinos, or the swimming pools. Not Michael

Michael had tipped his hand to Roth, by turning up without the $2 million

Then having the money brought over makes no sense to me. I too reckon Not very logical--the risk would have been enormous.
and no valid reason either. He had the plane waiting to take them to Miami in an hour. He wasn't hanging around to make a big buy-in.

Pacino's superb acting – Mentally wrecked, physically sick in great pain realizing that Fredo is the Family traitor
If Fredo had not revealed himself as the traitor in the family then all live happily for a hundred years -- the family.