IMO there's different kinds of "casual" as there's different kinds of "hardcore" that can't quite be captured by bullet points like this.

How would you call someone who doesn't do savage, yet has done all relic, collected all orchestrions, TT cards, sightseeing logs, mounts, minions? I would definitely qualify such a person as hardcore, probably more than some people grinding Savage. There's a bunch of people that live for achievement hunting that I know of and consider truly hardcore players, despite them not doing much savage.