In 1963, JFK ordered a complete withdrawal from Vietnam.

[Genki Hikari]

34. So why did he drastically increase troops to Vietnam before then?

Strange, the troops Ike had sent to Vietnam by 1960 had been 900. Here are the numbers during the JFK admin:

1961: 3205
1962: 11300
1963: 16300

http://www.americanwarlibrary.com/vietnam/vwatl.htm

So through 1963, JFK had increased the military personnel in Vietnam by a whopping 1800%. Please don't be ridiculous and say that LBJ sent those last 5000 between November 23 and December 31. It wouldn't be true, and we all know it.

Lowering Vietnam personnel by 1000 personnel was barely a 6% reduction in force, and was undoubtedly under consideration because JFK knew he looked bad at home and abroad for supporting Diem--until the South Vietnamese themselves took that thug out only three weeks before JFK himself was assassinated. Politicians dabbling in another country's affairs always start looking for potential outs when that same country goes through a violent transition of power.

I know people don't want to hear this, but in every single year of his Presidency, JFK supported overt and covert actions in Vietnam. Multiple records attest to this. Read the featured reports of the 1961-1963 period listed in the timeline on this page:

https://www.archives.gov/research/vietnam-war

Documents like this one show exactly how much he was committed to inserting military forces into Vietnam:

https://catalog.archives.gov/id/193504?objectPage=3

Or how he made it clear he didn't want to pull out of Vietnam unless public sentiment back home forced him to do so? I mean this is what he apparently sent to Diem in a letter in September of 1963:

I have said publicly that we do not wish to cut off our aid program at this time, and I shall not change this position except as such change becomes necessary in response to the democratic processes of this country. But it would be wrong for me not to let you know that such change is inevitable unless the situation in Vietnam can somehow take a major turn for the better.

https://catalog.archives.gov/id/193383

And yet the deteriorating situation in Vietnam wasn't enough to stop JFK'ssupport for South Vietnam exhibited by a two-pronged assault at Da Nang on 11 Nov 1963.

https://catalog.archives.gov/id/26392238

So much for wanting to leave Vietnam.

Even if he had asked for RIF plans, plenty of leaders consider alternative courses of action, for a whole lot of reasons, but that doesn't mean they implement any of those alternatives. The chances of JFK changing course aren't very high. He was a hard-core anti-Communist--by his own admission, and by his every action as both a Senator and as POTUS. There's every reason to believe he would have foregone any withdrawal plans when South Vietnam didn't descend into utter chaos after Diem was ousted. Because he certainly didn't seem to be interested in deescalation at Da Nang less than two weeks after Diem got whacked.

In the end, speculation about what JFK wanted to do or would have done is ridiculous. We can only go by what he actually did. And, for most of his term of office, he was quite happy to send military personnel to Vietnam, and to have them engage in a full array of military actions there.

That is reality.