Oh, I love this topic! I could make a thousand posts about the way Fredo is treated. Don't get me started... (Too late, you already did; but I promise to keep it under a thousand .)

And there's something else about that Vegas scene. Michael had castigated Moe Green for "slapping his brother around in public," and then at the end of the meeting, Moe hits Fredo AGAIN -- in front of everybody, even Michael. (Moe is so angry about Michael having the audacity to want to buy him out that, when he gets up from the table, we hear this crash, as though he's just swept a few of the plates and glasses from the table onto the floor. Then, when Fredo offers to smooth things over, Moe punches him -- or shoves him hard -- in the shoulder.)

Now Moe probably does this to show Michael he darn well won't take orders from any Corleone and he'll slap around whomever he pleases when he pleases. But to use Fredo as an example like this is just wrong. This is just one of the embarrassing episodes that build up and lead to Fredo's feelings of inadequacy until his desperate need to be of value leads him to collude with Roth and Ola.