pfft hell even with no brave bonus and a 20% over level penalty you should be able to rocket up to 15 f2p. lv 6 or 8 will be aquired in the harbor. Lv 12 will be reached just running tear/gwaylands as well as some marketplace ones. After that the lordsmarch quests and 12 quests (spinners) (free ones) should take you to 15 or 16.
With a real repeat grind you could probably even nail 20. But people usually tend to buy the vale pack for the XP and GS clickies. You just can't beat GS clickies.