Exploring the culpability of Fredo in The Godfather Part II

Hoping to get some discussion on one of my favorite movies of all time. Obviously there will be spoilers here, but the movie is 50+ years old. I think Godfather Part I and Part II are some of the best examples of "show, don't tell" movies of all time and thus reward rewatching. I have seen this movie probably a half dozen times and something that I have gone back and forth on is how deserving Fredo was to be killed at the end of Part II. That leads me to backtrack through the films to determine what he did to determine his level of guilt.

Big picture, Michael ordered the hit on Fredo because he cooperated with Johnny Ola/Roth which provided them the inside information needed for the attempted murder of Michael and his wife that takes place in the beginning of the movie. This makes sense.

However, towards the end of the film, Fredo gives a teary confession to Michael, saying that he didn't know that they were going to try to hit Michael. He just wanted something for his own, he was passed over for his younger brother and no one has ever respected him. Johnny Ola convinces Fredo that by passing information to Roth, Fredo will end up getting more independence from his brother and more respect from the Corleone family. This also makes sense and also explains why I feel sad watching Fredo get killed. Sure, he betrayed his family but he did so with somewhat positive intent, he didn't mean for this to happen.

Here's what's confusing to me: what information exactly would Fredo need to pass to Johnny Ola/Roth that would allow them to try to take out Michael?

1. They mention after the attempted murder that one of the bodyguards "disappeared" after the attack (I take this to mean that Fredo provided information to Johnny Ola about which guards would be susceptible to bribes to look the other way.)
2. They knew the exact room from the outside of the house that Michael slept in.
3. The fact that Michael kept the windows open during the summer time while he slept.

If you assume that this is the type of information that Fredo provided, how can you also take his teary confession that he was played by Johnny Ola and didn't know they were going to attack Michael? What did Fredo think Johnny Ola would do with this information? I know that Fredo is often portrayed as being the dumb one who no one respects but surely he would know that this sensitive information regarding the security of his brother would put his brother's life at risk?

So I ask.. was Fredo just a dumb puppet played by Johnny Ola and Roth with his head in the sand? Or was Fredo at least somewhat aware of what the outcomes would be of his actions?