Is teaching a God gifted art? If yes how much (in%) it is God-gifted and how much it can be attained through seeking/utilizing the opportunities?

teaching  - like many other things - is a blend !! 

People may have the interest and inclination towards being teachers (or something else), but they also need to develop the knowledge, technique and skill to communicate this knowledge to the students.

What I want to say is in brief,  God-gifted talent alone will not be enough, and trying to get the required skills  through training with no genuine interest in teaching will also not be enough !!