No, Wonder Woman is not brutal at all. And she definitely has 'qualms' about killing. But she does kill in battle when she has no other choice (which is rare, because she's so powerful).
And Superman 'definitely worthy'?
Not of wielding Mjölnir.
As for Sho: what is a warrior? A warrior is one who fights for what he believes is worthwhile - one who enters a battle from which he may not return, because his loved ones are in danger.
What is Sho, if not a warrior?