I think that the XP drop rate is too low, because i could die.. Loose 30xp, then kill 1 kobald and get 50xp.
Easy way of getting back to full hp/willpower.
Should be around the 100xp lost at level 6, then every level after that should loose 50more xp..So:
level 6 = 100xp lost
Level 7 = 150xp lost
level 8 = 200xp lost
Etc Etc.