The nests and mummy sarcophagi empty out after a while, and die by themselves. IIRC, any monster death gives exp, even the raised ones, and if no one got credit for the kill (like eggs bursting open), then everyone gets a share of the exp, provided they're in the same named area.
Spears are terribly slow, and will take some getting used to. Even if respec is unavailable, 1 point in some other mastery won't make or break the character, especially since Find Item isn't worth it. So IF you luck into something with good damage, you could always use it. However, a 3s pike with some skulls in it should do the trick. You're HC anyway, so you'll know to take measures against getting swarmed.
You may still want to level off of something other than maggot young until you get WW, because they spawn pretty plentiful.