Is this talk just a convention? In this question it was said that Buddha said  "I, the unexcelled teacher. I, alone, am rightly self-awakened ... I am a conqueror (of evil qualities)."
The answer seems to be that Buddha used 'I' for sake of convention.

Given Anatta , is the following talk a mere convention?

I have craving for music.
Do you have craving for ice-cream?

Is the 'I'and 'you' used in the talk above merely a convention or is it real?
It's all about mental context, my friend. If in your mind there's a (silent) conviction that you see, you act, you were born, you will die, this is you etc. - if your subjective experience is like that - then for you there is Self. Even if you don't use the word "I", there's is still belief in I in your mind.

If in your mind there's a silent understanding of how things work, how mind works, and how illusion of I is generated - then for you there's no "Self" or "No-Self" - you clearly see how it really is. Even if you use the word "I", there's no belief in I in your mind.

All talk is conventional, because "conventional" means we assume we are more or less in agreement what each word means. What matters is your mental context.