Factually, on civil rights, I think you're right, although JFK had gotten a civil-rights bill, although more watered-down than the one that passed under LBJ, through the House before he was killed. Like anything else about JFK post 11/22/63, we can only speculate; could Bobby, who was far more passionate about civil rights, have persuaded his brother to push for something stronger (the southern leadership in the Senate might have blocked it)? Or possibly JFK could have seen the increasing anger in the African-American community and taken the initiative, but who knows? As for Vietnam, JFK hoped to neutralize it by means of a coalition government much as he did in Laos in 1961, and we know that he had set a goal of getting all of our advisers out by the end of 1965. If conditions had changed, though, it is absolutely possible he would have committed more troops, although hopefully not the 500,000 that ended up there on LBJ's watch. Things might have altered his thinking after the assassination of Ngo Dinh Diem just three weeks before JFK's own murder.
But since this is a television board, let me get back to the specials that have been airing; I've only had a chance to watch the ones on National Geographic channel; I still feel the movie "Killing Kennedy" was too simplistic; the one about JFK's last 24 hours seemed to come down to a bunch of now-middle-aged women oohing and aahing over JFK's looks. I will say, though, that JFK's family was probably the last presidential family the American people really related to--and I think (and this is just my opinion) that was especially true if a family had young children. Larry Sabato, in his book "The Kennedy Half-Century," has even called the Kennedys a real-life version of some of the sitcom families of the era: the Nelsons, the Cleavers, the Reeds (he meant the Stones, on "The Donna Reed Show"), the Taylors ("The Andy Griffith Show"), and the Andersons ("Father Knows Best," which was in primetime reruns for much of the Kennedy era).
I like what Richard Reeves wrote about HBO's biography of RFK a few years ago in TV Guide: you had to be there to get Bobby, and after his assassination, for a time people wondered "what might have been?" "But in the end," says Reeves, "that question was directed at someone else--his big brother Jack."