You should do the ARC class quests because there are some new skills that you get after you complete them. The class quests are level 5, 10, 15, 20, 25, and 30. After the level 30 one the next quest from the guildmaster will say that you need level 15 PGL. Go back after you level the subclass and she'll direct you to the BRD quest npc. Complete the quest and you get the Soul of a Bard crystal to equip.

If you like a little story, you might like the ARC guild storyline. It was a little annoying at first, but I liked the resolution.

A little off topic but don't turn off the active help, it gives a lot of good game information. Have fun and welcome back!

PS- Please excuse the untidy post, just realized it's really late for me. @.@