The instance you are imagining will inevitably be inundated with the output of spambots. You don't want a completely unmoderated instance because it will just not be an enjoyable place (even for you! even for people who have no problem with getting exposed to "hate speech"!) to hang out on.
I think lemm.ee defederates from very little, that is the closest I know of, but I see that that's already where you are, so I can't help you much more than that.
Now that so many things we use every day have computers in them, many causes of death are related to computers.
Many modern cars (especially electric cars) are basically computers that drive; cars kill many people. The same applies to planes. Software bugs in medical software might cause you to receive improper care, which could kill you. Computers might control a lock which might lock you in a room until you die of dehydration or starvation.