This person(E) in the link says "character" is not "personality." Do you think it is really important to distinguish the two words in the conversation in the link?

Well, you haven't read carefully, because the answer is in there:

E: Yes. OK. Wisdom. And character. Do you mean personality, when you say character?

S: No. I mean character is more like integrity.

E: I see! Uh-huh.

S: Having a clear sense of right and wrong.

E: Yes, uh-huh.

S: Um, doing the right thing.

E: Uh-huh.

S: And, in life, everyone has to make decisions.

E: Uh-huh.

S: And all decisions have consequences.

E: Uh-huh, uh-huh.
He tells you exactly what he means by character, he means integrity.
And it is important to distinguish these words.

'Character' is deeper than 'personality'. It relates to the kind of person you are.

On the other hand, 'personality' is more superficial in a sense. It relates to how people see you, the kind of person they think you are.

Best wishes, Clive