I’m a WvW and PvE player and I have to change traits fairly often going between styles of play. Sometimes I forget to go the NPC and I’m already in a dungeon; if I am leader i’d have to wait until the dungeon is complete to change.
My suggestion is to allow us to buy a book for gold, say something like 20 gold, that allows a second traits line/build. That would suffice as it’s a few silver to change already.
Sanctum of Rall