1 is true. I have no idea if (2) and (3) are.
I also have no idea if Johnson and Hoover were really “close friends”. The most famous quote concerning LBJ and Hoover was that, when asked why LBJ did not fire Hoover, he is reported to have said something like “I’d rather have him inside the tent pissing out, than outside pissing in”, which hardly points to close friendship.
[From: Irving Wallace, The R Document, 1976] Rather, it points to what has often been alleged - that Hoover was simply too politically powerful, knew too much damaging stuff, to touch, and so could do as he pleased.
After all, Truman allegedly said Hoover transformed the FBI into his private secret police force; Truman stated that “we want no Gestapo or secret police. The FBI is tending in that direction. They are dabbling in sex-life scandals and plain blackmail. J. Edgar Hoover would give his right eye to take over, and all congressmen and senators are afraid of him” … yet Truman didn’t fire him, either.
Now, it is a valid criticism that these presidents really ought to have got rid of him, if they thought he was setting up a “Gestapo”. But that’s a diffeent issue, that directly attributing Hoover’s actions to them. It may well be the case that both are bad, but the one is bad for a different reason than the other.
The link you posted is to a lengthy conspiracy cite claiming a cover-up of the JFK assassination. I’d not put much weight on it.
Stripped of the hyperbole about “hysteria”, that’s more of an ‘I don’t care much about this inaccuracy’ response. Which is fair, but not the same as a ‘there is no inaccuracy’ response.
To my mind, it is really simple: did JFK actually inspire or approve of this tactic? If the answer is “no”, while the movie claims it is “yes”, there is an inaccuracy. It is one that tends to put disrepute on a historical character, so it makes sense that people would not like it.
A comparison would be with the other recent big history biopic, The Imitation Game, that had Turing blackmailed by a communist agent (which was pure fiction).