Admiral Piett might disagree, the Empire is full of evil people to be sure, but it rules through fear, people are cowed into evil because they live under a regime that normalizes it. This is actually a important aspect of the lore because its the actual manifestation of the conflict between the dark and light sides of the force, as the Empire's power grows it's influence on the people of the galaxy does so as well, and with that so does the dark side.
More apropos is a little fellow named Jabba the Hutt. We meet exactly one Hutt in all the (original) movies, he happens to be a big gangster, but because one-out-of-one of the Hutts we meet is a gangster, it means that %100 of all Hutts are now kingpins of the galactic underworld. So really he should be called Jabba the Tatooiner because calling him Hutt is a bit redundant. Assuming that Hutt was his species anyway. I wouldn't have an issue with this in most fantasy settings because morality can be inherent, it can be magically something you're preordained to, or it can just be something you are naturally predisposed of, like goblins and gnolls; but in Star Wars being good and evil is all about something called the Force, so having entire races of gangsters kind of doesn't totally jibe with it. It would have been better if the Hutts were a race of super mercantile types among whom the less scrupulous could easily fit into such underworld roles. Considering most of this is still just EU lore, that could still end up being the case.
As for killing goblin children, you interact enough with them and are shown enough of their rearing to understand that they're as ruthless and bloodthirsty as their elders to make it not seem so outrageous (I do K.O. them to be honest).
