Well, it really depends on the specific manga. Some might explore the idea, but many present a more nuanced view where evil is a result of circumstances and choices rather than an inherent trait at birth.
Well, I think it depends. Sometimes the portrayal of ghosts in manhwa is so imaginative that it's hard to take it seriously. But in some cases, they can add an element of mystery and excitement. So, I'm kind of on the fence about believing in them.
In my opinion, there are elements in Chapter 6 that could be interpreted as fate, but it's not a straightforward conclusion. There are multiple factors at work that might influence one's belief.