Originally Posted by
Grocalis
Be aware, that those ages listed in the WC3 manual may no longer be accurate. The War of the Ancients Trilogy implied that Tyrande, Illidan, and Malfurion were young. So young that all of them were "novices" in their chosen paths, with no hints of them having older professions. (If they were even just over a 1000 years old by the WOTA, then they would have had hundreds of years as an adult to do something else.)
As for Azshara, it depends on how the Night Elves in the beginning were ruled. Azshara was known as powerful in the arts of manipulation, so much that even Illidan, after getting blessed by Sargeras, had trouble not falling under her spell. Considering new lore being discovered in Pandaria, lore that implies Night Elves did exist for a short time as slaves of the Zandalari, it could be that Azshara herself was born a Night Elf and simply was one of the first to discover the connection they had to the WoE, a connection they would go on to destroy the troll empires and seat themselves at the top.