We can learn a few things about JFK's leadership, however brief it was.
One thing I have noticed when I have watched the old footage from his days as president and even before is he almost always had a smile on his face. He seemed to be a happy person despite health issues, and I think people responded to him, and to Jackie, in kind. Of course JFK could be serious, but most of the footage shows him smiling at crowds, cracking jokes, and so forth. He might have had a temper, like Bill Clinton was known to have on occasion, but it's hard to picture it with JFK.
Alleged historians, as opposed to real ones, including fakers like Horowitz and Collier who had a political agenda to push under the guise of "biography," tried to tarnish the Kennedy family as a bunch of corrupt no-goods, sociopaths even, whose tragedies didn't deserve any kind of sympathy, that the grief many of us went through during those four days in November fifty years ago wasn't real. That "revisionist" con job was especially pronounced during the 1980s, when Ronald Reagan was president, in some ideologues' desire to tear down idols and put new ones in their place. It was pretty obvious it was a con job, and it always pissed me off. There is still some of that today, but it isn't as bad as it was twenty or so years ago. The Jack-Jackie marriage was especially vulnerable to b.s. examination, but almost all reliable accounts have it that they were getting much closer after the death of their infant son just a few months before the assassination. The body language in those old films prior to the assassination shows as much. JFK may not have always treated Jackie well, but it is obvious that towards the end he realized she was the best thing he had going for him. He was very proud of her, and it showed. Damn it to hell Oswald ruined that and God knows what Jackie went through all of those decades before she died reliving that murder. She must have suffered from PTSD and had nightmares for years. I hope I am wrong about that. I hope that she never had any memory of what happened. I hope she never saw the Zapruder film (I can't even look at the thing myself). I've seen interviews with Clint Hill, the Secret Service agent who jumped aboard the limo as the assassination happened (and is the last surviving passenger), and he was practically in tears all these years later recalling what Jackie did after the third shot and why she did it. It's just too horrible to think that she remembered any of that.
Here are some short videos, from the Von Pein YouTube channel and elsewhere, about the events of that fateful day. These are local reports or amateur films:
JFK's breakfast speech coverage by KRLD:
Parking lot speech, audio only:
Love Field landing coverage from KRLD:
Clint Hill talks with Scott Pelley about the assassinaton:
Horrific beyond belief. I don't know how Jackie Kennedy ever functioned after that.