Responses
While it's true that he is insecure about his acting, I understand why he values Seojun's opinion... After all, Seojun may be only 10 years old but his achievements are goals that not a lot of actors have achieved.
Add to that, the fact that Seojun is using a skill. If I remember correctly(from the novel), Dohun was considered by the skill to be a part of Seojun's pride(a group of lion).
But I do agree that it is an unhealthy dependence on another person's opinion even without considering the fantasy concept of Seojun's abilities.
He's 10, i mean that’s a bit overly dependent on a 10 year olds opinion, if i were getting complimented everyday by a 10 year old i’d assume the kid admired me and or was getting brownie points, taking it seriously really shows how insecure that guy is