Earthborn said:
A lot of text snipped for band-width.
I don't think there is at this time any reason to assume it is impossible to outdo nature, and create a world without death and suffering. Whether people will care enough is a different matter.
You seem (to me) to be making the common fallacy of thinking animal = mammal.
MOST predators are not mammals. Most prey (both in numbers and in biomass) are not killed and eaten by mammals. Spiders eat more kg of meat than lions, cheetahs, and probably all other cats *combined*. Ants probably eat more meat than all non-human mammals combined.
The thing to remember here is that the larger the animal, the more food it needs, so the less there can be of said animal. And to maintain prey, it has to be a LOT less of the big predators than the small ones. This translates into a few lions and a LOT of ants.
And this brings us to the real issue of my reply:
MOST predators do not learn hunting and killing for food. They are hard-wired to do so, as they would die off as a species in about one year if they weren't.
You can't teach a spider, a scorpion, an ant or a venus flytrap not to kill it's prey. OK, you can feed the flytrap, but you can't teach it not to kill the occational fly landing in it.
And spiders, scorpions and ants kill larger number of animals than all mammals combined. They even kill&eat more kg of animals. Which, considering the size of their prey, says something about the number of kills they do.
And fish... You can't teach fish not to eat fish, not all fish, anyway.
This boils down to you having to "manually" feed *every single predator* on the planet. Or kill them. How do you feed 1.000.000.000.000 ants in order to avoid any of them to ruin your day by feeding themselves?
In short: It can't be done without reducing the number of predators in the world drastically. There is not enough energy available to do it, by machine or by hand.
Mosquito - standing up for "the little guys"