The ethical considerations of time travel

[SepiaAndDust]

I haven't worked on my time travel story in quite a while, but I'd still like to have the discussion.

Conceits:
1. The past can be changed. You can stop the JFK assassination, and the world you return to will be different.
2. The time traveler is not directly affected by the altered timeline. You can kill your own parents before you were born, and that will alter the world you return to, but you won't cease to exist. You'll be a person without a personal history as far as records go.
3. You travel through time in an actual time machine. It's pretty hardy, but it can be destroyed. There is only one (though future time machines can't be ruled out.) The time machine also cannot be "uninvented." Kill its creators in the crib, and the machine will continue to exist as a thing without an origin.
4. No travel to the present's future (it literally doesn't exist), just to the past and a return to the present.
5. Time passes in the present while you're in the past. Spend 2 days in the past, and the present you return to will be 2 days later than when you left.

Questions:
Do you have an ethical obligation to right wrongs? To stop the MLK and JFK assassinations. To save George Floyd. To warn the commanders at Pearl Harbor or the people inside the twin towers on 9/11 (whether you'd be taken seriously is another matter). Should you give the police the names of serial killers active at that time?

Or more personally, are you obligated to save your daughter from the drunk driver who put her in a wheelchair? To warn your father to get checked for the aneurysm that killed him? To shoot that rabid skunk before it meets your childhood pet?

Or is the current timeline sacred to you? Make one change, and lots of people may never be born. Is that the same thing as killing them?

[SepiaAndDust]

The genesis of my story came when I watched Timeless a year or so ago. I started wondering what I would do with a time machine.

First, I went through the fluff. Save MLK, stop 9/11, kill Hitler. Then I figured nah, we as a society need lessons like those every so often. We can't really get better on our own without going through hell first, and we have short memories.

Then I wondered whether I would save my friend who died long ago at age 12. She was killed by a bad diagnosis, and a relatively simple surgery would have saved her. I thought and I thought, and I decided that yes, I would save her, that god himself couldn't stop me from at least trying.

Even if I had to do bad stuff, like kidnapping a 12-year-old and holding an ER team at gunpoint.

On that, screw the timeline, forget how things are "supposed" to be, and whoever doesn't get born because of my fiddling with time just doesn't get born. Maybe god himself even ordained that I get a time machine so that I could (dangerous thinking in its own right).

So that's where I'm coming from. Lots of ethical questions. Lots of philosophy.