PSO2 worth coming back to in 2018?

[Anduril]

Nope, instead it's locked behind Buster Quests, but at least you don't have to wait for 7 people to join before being able to progress now.

Actually, you don't even need to play the Buster Quest portions of the story; they can be skipped altogether except for the first tutorial one where you just have a single tower.

[wefwq]

The situation you describe is more or less happened in this game, too.
Though if you're been away for awhile, hero is actually really fun to play.
If you're in for content, avoid the game.