I see your distinction and I think it is about moderation and structure. A community has rules, it has guidelines and a collective emergent morality. A collective is a hierarchy in which power is usually wielded by the loudest or 'most qualified'. Both exist within every group of people - and whether it turns into a totalitarian collective or a community which finds comfort is often down on the granular level. A big part of what I object to on Medium is a push towards a left-wing progressive collective (even though I'm politically aligned) and would prefer an emergent community which allows differences of opinion.

Destructive, difficult people and problematic behaviours is a fairly good description. I don't mind the label applied, in reality the two things remain the same. I work with EUPD patients a lot and we could call them DDPwPBP if we were so inclined - but we're still dealing with and talking about the same thing