Ethically, I think one could justify all this. It is hard to argue, for example, that we (real human beings) have been harmed by being brought into existence in a universe without a God who is listening; almost all of us would prefer to be alive rather not. The same would go for them: surely, their simulated existence, imperfect as it is, is not worse than not having been brought into the world in the first place?

At least some of them will tell you they had rather not been born. But maybe you'll want to equip these orcs with an even stronger drive for existence, so they never choose death over life even if you torture them; would that make it more ok? I suspect not, so something with the "Do they complain to having been created?" approach seems flawed imo. Creating beings with a strong preference for existence would make it too easy to legitimize doing with them whatever you want.

How about imagining beings who at any moment are intrinsically indifferent to whether they exist or not? They only won't complain as long as they don't suffer. Perhaps that's too extreme as well, but if it's only simple/elegant rules you're looking for, this one seems more acceptable to me than the torture-bots above.