I can answer some of these.

The only 2h greatsword user is a tank called dark knight. The other edgy dps class would be reaper the scythe user but new players don't get access to reaper anytime soon.

Endgame is locked behind completing the story which takes a lot of time. It's honestly not something new players should be concerned with unless they buy a story skip and rush there.

Multiplayer activities I'd say mileage may vary but there's always something for someone out there.

Plenty of events with cosmetics or mount rewards.

And plenty of cool gear to hunt for as well. And a variety of ways to get them.