I know remote gun operation with servos and scoped cameras are a thing. You can definitely get or make them yourself. They are legal in the USA at least.
This is extremely misleading. In the US, the ATF has stated in past rulings that electronically-fired semi-auto weapons are functionally equivalent to full auto weapons in the case where there is not manual user input per shot. (If there is manual user input per shot, it's not clear from any existing rulings and should be treated as an open question that may get you sent to prison).
Now, the ATF just makes up new rulings all the time and they aren't laws, so "legal" is always a touch fuzzy where the ATF is concerned, but you're probably going to prison for a very, very long time on a weapons charge if you make a remote-activated, electronically-fired semi auto like we're talking about here - the same way you would be if you try to make your own full auto. The exception would be the case where you are legally allowed to manufacture fully automatic weapons because you have an SOT license from the ATF. In the case of the video made in the past few months where some YouTubers mounted a rifle on a Boston Dynamics Spot, one of the YouTubers in question specifically does have an SOT, meaning they can do things that would get normal people sent to prison over an NFA violation.
At the very least, before you do something that destroys your life, call up the ATF and ask them whether what you are about to do is a dangerously bad idea legally.
Yes, you can't just make an electronic finger that pulls the trigger at 100 rounds per minute if you hold down spacebar. But I was thinking more along the lines of this:
I figure if a human is operating a "remote gun" the relative psychological impact would be similar why casinos have you bet with poker chips instead of actual cash—you may be more likely to pull the trigger, because the impact won't be as real to you. (I wonder if there's any data or studies around things like this?)
For drone pilots, it's rumored they actually have a lot of PTSD. You may be looking at a screen and ignore the situation now, but for healthy humans, killing someone will ALWAYS come back to haunt you, even if it's entirely justified like in self defense.
I think that is pretty speculative. I think a large portion on the population would not be haunted by killing others in a wide range of justified situations, particularly when it comes to defending themselves or family from a credible threat.
To be honest, I think I would be more horrified. There is something surreal and disgusting about the thought of killing in such a way. Similar to the horror of the Rube Goldbergesque devices used in the Saw films. However, if you put it through a filter to make it look like a game and pull and Ender's Game on the user, you may get the psychological distancing you mention.