Thank you for your extensive comment, I will go through everything one subject at a time;

Originally Posted by OneManArmy
On this, work on "Kagha root" ended and the problems began:

1. The task of Kagha is not clear when she says that we should deal with the tieflings after Zevlor's death. I killed everyone, When trying to kill tieflings (the girl's parents), druids become aggressive. I don't understand what she wants from me.
2. Immortal tiefling children ... oh, this looks like a bug, not censorship. Let them just run away somewhere when I start killing adult tieflings, okay?
3. When we go to the camp, there is a note in the journal that the tieflings left the camp.
When we return we see this picture: the children of the tieflings are still in the grove of the druids, and the druids have become aggressive. Not a single dialogue, they are just aggressive and that's it. Why? I helped Kagha!
4. When I killed all the other tieflings and came to the Kagha, there is no option to report it to her.
5. There is no reward for killing tieflings. I would like some simple artifact, the right to visit the grove (we are not refugees, but the guests who helped them), and a potential ally of the Kaga if she meets us in the next acts.
6. No vine has grown, the rite is not complete.
7. We have the label "hiding from the law", it is incorrect, we are enemies of tieflings in the grove of druids but not the law.
8. The lack of an adequate response to my actions from all tieflings
You ran into the bug / feature of certain druids acting as generic guard NPC's responsible for crime handling in the entire grove, not taking into account that they actually hate the Tieflings. Until separate flags are set up for the ritual site area and the caves, this is going to keep popping up like it did in 1, 3 and 7.
Originally Posted by OneManArmy
Perhaps she doesn't need to be a Shadow Druid, just a Druid vying for power with the Khalsin. We already have evil heroes, it should be made neutral.
If we help her, we should have a task from Kagha to resolve the situation with Mintara peacefully (a truly neutral path, or possibly neutral evil depending on the player's decision) or kill the goblin leaders (a neutral good path for lovers of elves and druids, which will be no different from helping the tieflings, except for the fact that on the party will be druids)
Can only agree here. Olodan makes things unnescessarily complicated (where did she come from? how did she manipulate the entire grove into following her?). I don't think Minthara would want to cooperate with the druids as Sylvanus is a serious threat in the region for some reason.
Originally Posted by OneManArmy
In general, there are a lot of things to think about if it won't be difficult for Larian.
The druids can either become Minthar's neutrality/allies, or replace the tieflings at the party - for ex
Larian can remove this possibility altogether, it would be better than leaving the illusion of choice with a dead end.

I don't want this to be an extra waste of resources that can be spent on more important quests, but the Kagha root in the form in which it is in the game is now completely unplayable. At least cosmetic improvements are needed so that there is no feeling of "dead end"
There should be at least something for Kagha in the long run, yes. I think she is meant as a one-off character and that druids in general might not even become important again after Act 1, so her character and faction seem irrelevant now.
Originally Posted by OneManArmy
I think a possible "neutral" root was buried here. There is no reason to help Kagha now, it doesn't look like a path - it looks like a dead end.
It's not a path, I don't know why people keep saying it is. There are only two paths, the Tieflings and the Goblins. Making Kagha a third path would be great and something I would encourage if Larian does not want to rewrite her.