Addons
As far as I know, there are no addons. Quests are the heart icons on the maps.. kill the mobs or complete those activities around those areas and you’ll complete it.
Nope. That’s because there are no traditional quests. Quests in this game are dynamic events. Don’t worry about being most efficient. It’s a terrible way to play this game anyway. In WoW you wanted to level to get to raids. There’s a lot less of that in this game.
Basically, look for hearts on your map, talk to the heart people (or not you don’t have to) and start helping out. Doing stuff around hearts helps you fill them.
The hearts are there to keep you in the area where dynamic events spawn. That’s your real bread and butter. Events are repeatable, and often chain into longer chains, so don’t run off immediately after finishing one.
I’d also recommending joining a friendly, helpful guild. It can make your experience much better in game.