Fighters, Mages, and Undaunted daily quests can be shared in a group so I would think that these can be completed similar to how the Wrothgar world bosses can be completed.
The Vegemite Knight
"if the skeleton kills you, your dps is too low."~STEVIL
The Elder World of WarScrollCraft Online~joaaocaampos
You're better off looking for books instead. Much faster. But yes, dailies will increase skill line.
Yes, the quests offer a small amount to level up the guild quest line, but it is equal to one or two books so the reply I quoted is the correct answer.
The only real reason to do the daily guild quests is a chance at a motif, but it has a low drop rate.