Mark Grayson isn't Asian. The creators of the comics have established his ethnicity as something other than Asian. This is a well-defined aspect of the character's portrayal.
Hard to say. To determine if it's a true story, we'd need to know more details about the origin and sources related to Jennifer Grayson. Sometimes stories are inspired by real life but have fictional elements added.
Mark Grayson isn't Asian in the comics. This aspect of his character has been consistently portrayed throughout the various comic storylines and depictions. There's no indication of him having Asian ethnicity.
The Great Elven Sage was Nolan's novel, and A Noble Son Picked Up was Lu Zhen's novel. I hope my recommendation can help you. If you like it, join the book group as soon as possible to discuss it.