Alright, so I understand that I should have to complete Whispering Hillock before a certain point. Stupid IGN says before starting Ladies of the Wood. The Witcher Wiki says it's before you speak with the Ealdorman of Downwarren. So i'm not entirely sure.

What EXACTLY are the requirements? I have Ladies of the Wood active. But I haven't followed the trail of treats yet. Can I go find the Whispering Hillock and complete it now, or do I have to do it before the Ladies of the Wood quest is active altogether?

The requirements for saving Anna is that you carry out the crones' wishes (kill the spirit) IF you speak to them and haven't killed the spirit yet, ie. spirit still alive; spoken to crones; must kill spirit.
OR
IF you have not seen the crones yet, you can kill or free the spirit and Anna will be spared, because she hasn't (in their eyes) broken any promise, which is what happens if you speak to them and then let the spirit go.

TL;DR, If you want to free the spirit, you MUST free it BEFORE you speak to the crones if Anna is to be saved (taken to Blue Mountains by Bloody Baron). If you want to kill it, you can go straight to the crones and do their bidding or kill it and then go to the crones (doesn't matter).

In any event, if you free the spirit, Downwarren will be decimated by the evil thing...

I have Ladies of the Wood ACTIVE, yes. But I haven't spoken to the Crones. This is where the confusion is. IGN says it can only be done before you get Ladies of the Wood. I have yet to even follow the trail of treats, so then I should be good?

If by "it" you mean 'Whispering Hillock' then IGN is wrong. You can do it any time you wish. The only proviso is like I said: if you wish to free the spirit AND spare Anna, do "it" BEFORE you talk to the crones. If you don't want to spare the tree spirit, talk to the crones first and they will give you the task of killing it. If you kill it as per their instructions, Anna will be spared. She only gets irreversably cursed if you go against their wishes. If you've already done Whispering Hillock before you ever talk to the crones, you haven't gone against their wishes.

I'm not saying you're being unclear. It makes sense. But what exactly are the qualifiers? Not talking to the Crones? Ladies of the Wood is active. The action of actually TALKING TO THEM makes it so you can only kill the spirit to save Anna.

Is this specifically dependant on quest stages or which quest is just active in general is what i'm talking about here. And from what i've read, you can only start Whispering Hillock by either finding the tree yourself or by speaking to the Ealdorman in Downwarren. I never knew the Crones could give you the task. Strange.

No, it's a quest designed around another quest. If you go outside that the game doesn't quite know what to do. You are supposed to go to the crones first. If you go and do the hillock first, the game has to do something the questline is not designed to do. Anna is supposed to be cursed if you let the spirit go, because the crones take it as a refusal to do their bidding and they blame Anna. However, if you do the hillock outside of the intended questline they have nobody to blame. THAT is the qualifier. Do the hillock before the crones have given you the task (ie. talk to them after) and the intended questline is buggered up, hence you can let the spirit go and spare Anna -- not supposed to happen, but it does.

The crones give you the task via the Ealdorman.

This is the way I've always done it if I intend to let the spirit go and ostensibly save the children but doom the town while keeping the good option open for the Baron.