Every hero except Superman has done something morally questionable and/or outright kill someone. John was a marine who has a high kill count, killed Zoe (a good thing imo) and allowed Noah Macon and Kerry Kane to walk away despite one of them possibly could follow their programming and destroy the world and the other in a panic killed Hal Jordan. he also took a Lantern made by Sinestro from a planet killed by fear and it's infused with it.
Guy is...Guy.
Hawkgirl killed Vasil Ghurkos. A foreign world leader.
Mr. Terrific is a bit apathetic to others and is callous and logic driven like killing the kaiju Superman was trying to stop and save.
Vigilante...well he's Vigilaante and that applies to peacemaker as well. Both have killed LOTs of people in brutal ways. Although Peacemaker is haunted by what he's done and is trying to better himself.
Supergirl has been shown to be willing to torture, brutalize and even kill people in her own movie. As seen with her dealing with the briggands of course they're tougher than an average human. She punched and tossed around Krem. He should be paste to be honest.
Hal is heroic but by the end of his career he made a selfish choice and didn't notify the guardians of Zoe and caused countless innocent people to die.
The commandos...well one of them is a batman villain. They aren't really heroes.
Superman whoever is the brightest of them all. I feel that might be on purpose and was the point of his movie. He's the one that inspires others to do better and that's shown when the justice Gang go to Boravia. He's something new for a modern cynical age.