Please advise if an article needed in "They arrived in _____ early morning."

When you want to ask how long the flight is, is it ok to say: How long is the duration of the flight? How long is the flight duration? or it't better ask How long is the flight? How long does the flight take?

Is it OK to say 'a strong teacher' if you want to say that the teacher is good, skilled, and competent?

Can we say 'junk food abuse' by analogy with 'drug abuse' or how can we say 'He overeats / overuses junk food'? with the meaning 'He eats too much junk food' ?

Is it okay to name a beauty studio "Self Love" ?

Please advise, which is better to say 'speaking of me, i prefer ...' . 'speaking of myself, I prefer ...' or 'As for me, I prefer ...'

Please advise if it's ok to say I wish you well on your school exams

Please advice which is better to say How long does it take FOR your company to deliver ? OR How long does it take your company to deliver ?