1. Nettie only kills you, if you are really bad. She uses that as a last resort, when you don't work with her at all, because she and Halsin where just attacked by a tadpoled person and she is afraid, you might attack the grove. She is doing exactly, what most cautious people would do in her situation.
2. Freeing Halsin doesn't require killing goblin children at all. Those two never died in my playthrough - that is entirely your decision, if they die. Helping Minthara kills children though, without any chance otherwise.
3. Those goblins, that are not hostile, just attacked people in the wilderness, killed and roasted a dwarf and burnt down an inn, killing a lot of innocents.
So yeah, you were saying about siding with Minthara is not evil?
Why should I work with her? I don't know her, she is a druid from the grove, a lot of them already were not very nice to me, and they want to get rid of the thiefling refugees. So I should just trust her blindly with my tadpole problem? Or the artifact? You know, the thing everyone and their mothers are looking for?