I’m going to try lvl’ing only by reviving players/NPC’s.
The XP for reviving is about half the amount of XP for harvesting, but it’s doable in the starting area. I don’t think the Village of Shaemoor, Soren Draa, the Village of Smokestead, Snowlord’s Gate and the Village of Astorea have any harvestable nodes without exploring other parts than the exact area you started in.
Now I only need a way to get players or NPC’s killed there without touching them ;-)
EDIT: Players can’t die in the tutorial/starting area