Here's what I think SE should do:
-Add more facial features like larger eyes, rounder jawlines, bigger ears for Miqo'te, smaller horns for Au'Ra, etc., so players can have a more youthful/baby-faced look without being actual children. More character customization is always a plus and I'm surprise SE hasn't add more facial features since launch.
-Add a more youthful looking race. Heal showed a good example with that Viera concept art. So long as they don't get a hyper-sexualized and/or deformed as the Elin in Tera Online...Because that's creepy.