I love it that he got killed while fishing before he had a chance to kill any fish.
"Please vote to preserve the unique character of Warren…" - Robert Duvall

Well… yes… I mean, he basically put the life of Michael, his wife and children in danger. Okay, he initially didn't know it was going to be a hit. But as you said, even after knowing what happened, he didn't end his association with the people responsible.
Didn't he try, though? There's that scene where he gets a call in the middle of the night, and flat-out says, "You didn't say it was going to be a hit…I'm out. Don't call me anymore." (If memory serves, at least, that's the dialogue, but I know it's along those lines.)
Where Fredo really erred there–aside from being dumb enough to believe all of that, which shows what a liability he was–was in not coming clean with Michael right away. You could say he didn't because he was scared (as he obviously was, when he ran away in Cuba and disappeared), but isn't that itself a problem? Doesn't that in itself prove that Fredo's loyalty was never to Michael, that he never trusted Michael as he should have? In not trusting Michael, he took sides against Michael. He should have gone to Michael the minute they made him the offer, of course, but when he didn't, when he saw they'd lied to him, he should have gone to Michael then.
Do you think it would have been different, if he had? If Fredo had gone to Michael after the failed hit, stood up, admitted what he did and why…do you think that might have proven to Michael that at least his brother was still "with him," and saved his life?
In other words, was it his participation in the plot that dug his own grave, or was it his failure to own up to it and prove that even though he erred, his loyalty was still to Michael and his family?
I tend to view this question (did Fredo have to die) as a sort of litmus test: if you think Michael could have let Fredo live ("for old times' sake?"), then that tells me something about you. My MIL always argues that Michael could have let Fredo live. Anyone else see this question/issue that way?
Even Mike himself regretted it later, as we saw in part 3.
You've lost me here. They never made a part 3. Such a film does not exist, which is good, because if it did, it would totally destroy the characters and story and would just be a big embarrassing mess, much better forgotten and never mentioned again. Don't you think?

Well… yes… I mean, he basically put the life of Michael, his wife and children in danger. Okay, he initially didn't know it was going to be a hit. But as you said, even after knowing what happened, he didn't end his association with the people responsible.
However, Michael is his brother, so this is a very hot debate. Even Mike himself regretted it later, as we saw in part 3. He probably should had thought more throughout before taking this decision. He might had gotten people he trusted watch him constantly to make sure he doesn't try anything funny again.
But yeah… in a way, he dug his own grave.
"You're a disease, and I'm the cure!" - Marion "Cobra" Cobretti

Why post spoilers in the title? They show up under "Film General" and "General Discussion"…

Yeah, he definitely deserved it.
Also helped by the fact that the actor looks quite ratty, slimy and untrustworthy to begin with.
That's not an insult to John Cazale (RIP), he's a great actor. Also liked his role in
The Deer Hunter
, even if it was more of a minor character.

Jeez!! Imagine if Fredo was really Underboss, or even Boss by succession if Don Corleane had been killed before he named Michael as his successor. The family would have been in some troubles, hana.
Fredo was a liability, and the best hope for him was being despatched off to some far away place to keep him out of trouble. Exact like when he was Mow Greene's lacket, hana.
But when he was discover him betray Mighcull, then Fraydough must go, hana.