I created a similar thread and showed all my suggestions there:
But I will mention the most important things for me:
Of course better, more nocturnal light
Create proper city inside a tree. Heart of Amidrassil should become a central part of NE culture. Let’s build a temple around the heart. In the real world, entire temples are built dedicated to a single relic. There is perhaps nothing more precious to night elves than a seed given by their goddesses. Let’s place the main altar in front of heart and above let’s build a large statue of Haidene from which the moonwell water waters the heart so that it grows stronger. All in Suramar/Darnassus and Wellspring temple style.
Bel’ameth become important for Shamans, mages and hunters of Azeroth.
More dragons protecting area.
Portals to the city should be much larger and better defended from Kalimdor side.
Exactly that’s why Amirdrassil is a great explanation of why we still have contact with the shadowlands. Beings from outside cannot get to SL, but the tree is a gift from the land of the dead. The Ethernal one’s trusted us enough to give us a portion of their power. The tree itself was created by the goddesses of death. Part of his power comes from death and become most powerful source of death on planet next to ice crown. It is the voluntary choice of the gods of death to unite our planet with their realms. Connection to Emerald Dream already link tree to Ardenweald. Creatures from the Dream can easily walk among the roots of Amirdrassil, so the creatures from Ardenweald will surely find a way to reach it too.