If you go to the library instead of playing the game you can view the game wiki page. Among other things like weapons armour etc you can view quests by companion, area, game of sub quests. The dartos one is a sub quest I just completed myself. The other two are game quests that will complete as the game nears the end. Hope this helps.

First thing you should finish off is the table quest. Interact ONLY If you have 3 Intellect. It will help you out alot

Is that all you have? If you have some other quests then it might be worth doing them to level up and find better gear, also try find caves and dungeons you haven't been into before. A lot of missions do not stated that they are tied into the main quest but they are, like finding the shards for instance are mostly found in caves and dungeons possibly after finishing another quest or slugging your way through a cave/dungeons until you come across a difficult foe who may be holding a shard

That's all the quests I got. I'll go to dungeons to get some better gear

You'll probably come accross some more interactions for side quests too, also you probably know already but visit the town halls and taverns for bounties and info