1) Purifying the Tree feels anticlimatic. It takes a lot to complete it, its a long duration thing and you only earn +10 alchemy as a reward. Unless it was supposed to not be a long duration or it was supposed to reward you with +100 alchemy. It might be nice for it to unlock a questline too, as its a magical talking tree after all. Maybe you need Ecomancy to advance it further?
2) Forging the Moon sword feels like it needs a buff. Its a lot harder to get mithril and the sword grants +100 power and +20 crafting vs Crystal arrows that can be done 5 times and each time grant +100 power and +30 crafting. Maybe the moon sword unlocks a questline to use it, or maybe enchant it to make it even more impressive. Like turning the Moon Sword into Quel'Serrar after defeating a dragon and forging it in its blood.
3) Killing the direwolf grants you a pelt. I see you can get Leather Armor from regular wolves, but nothing yet for the Direwolf. Or maybe you need a direwolf pelt with some other questline completed to make an even more impressive armor. Maybe one using Mithril, to go with your Moon Sword?