The first is unnatural; the second is unlikely: he's either a teacher or he isn't.
You might hear
'James is considered by some to be the best singer in the choir'.
'James is considered to be disrespectful of authority.'
I don't like 'considered as'; I prefer 'thought of as'.
'James is thought of as a role model for his younger brothers.'
Many other answers are possible.
Student or Learner