My understanding is the reason for the "Michael Corleone says hello" statement was so that Frank would believe that Michael had ordered a hit on him. And yes, Frankie does realize this. It was the reason he was going to testify aganist Michael.
So you believe that the strangling was only to scare Pentangeli and not kill him? You believe that the cop who walked in (ending the strangling) was a part of the plan???
