Skeptic

Of course there were reasons to select him, he was am expert in assassinations of world leaders, after all, but those reasons should have been overridden by the clear and obvious conflict of interest.

He planned the coups in Iran, Guatemala and Cuba but those didn't involve any assassinations. Is Dulles being an assassin part of the conspiracy as well? No evidence seems to exist.

But lets grant that because even then there is more plausible explanation why LBJ selected him for the board. The public at the time had no knowledge of the Kennedy administrations involvement in the bay of pigs disaster, Johnson wanted someone on the commission to make sure no awkward questions got asked.

He may have had a grudge and there may have been people still loyal to him in the intelligence community, but it's also a question of power and ideology. The Kennedy assassination allowed the intelligence community, that Dulles spent his whole career building and strengthening, to increase its power. By demonstrating that they have the means to assassinate a president who steps out of line, they can exert control over future presidents, and no president since Kennedy has gone so directly against the wishes of the intelligence community. Furthermore, following the failure of The Bay of Pigs, Kennedy became somewhat more inclined towards deescalation and coexistence with socialist countries and his firing of Dulles was only a part of that. Dulles' whole career was directly contrary to that approach, and he had had people killed over much lower stakes than that.

And how many people were involved with this? Because it sounds like every single CIA director (and probably a few deputies) since then would have to be "in on it". And not one person has said something, or accidentally dropped a receipt or a recording or any physical evidence whatsoever? Sort of like the Moon landing conspiracy.

Had tried to defect to the Soviets. Tried and failed.

He lived in Minsk for three years working at an electronics factory. He wasn't booted out by the Soviets, he returned to the US of his own will. But why is his failure to defect important for you to dispute? Surely its completely immaterial? How would him being a communist affect the narrative?

"I am starting to reconsider my desire about staying [in the USSR]. The work is drab, the money I get has nowhere to be spent. No nightclubs or bowling alleys, no places of recreation except the trade union dances. I have had enough."

Ironically quoting something that disproves your assertion above that he hadn't defected.

Allegedly. If there had been proof of that, he wouldn't have been walking free.

The bullet was eventually linked to a gun Oswald owned and Mrs Oswald testified that he did it, but this didn't come out until later.

No. For years I fully accepted the official story and wrote off alternatives as conspiracy theories, without looking into it. I changed my mind because I became aware of actual reasons to be suspicious, such as the breach in custody of the bullet and the conflict of interest with Dulles. The evidence is extremely shaky, which is very much consistent with the idea of a cover up. Before becoming aware of that evidence, I was willing to accept the official narrative.

No investigation is perfect and the more plausible explanation is mistakes happen. In order for it not to be a mistake, it has to be part of a chain of deliberate events each with its own probability of being true and each with its own chance of going wrong. So we have to deny the possibility that a single mistake is the plausible explanation in order to allow us to believe that the very implausible event chain (ongoing apparently) of hundreds of possibilities all compounding was executed flawlessly, is true.

That's why it's stupid. I'm not trying to convince you otherwise so please don't take my points above as worthy of responding to, I just wanted to tease out where the cognitive leap was.