I'm currently working on this story to improve it. I found some things I wasn't that happy with and am currently making a few changes to the story.
For one, I will introduce Robert's bloodline early on. He will inherit the Asgardian bloodline, but not to the point where he is as powerful as Thor in the comics. It will be adapted to the world and grow as he ages.
Also, he will be Robert Baratheon; basically, he will take the position equivalent to Odin.