A fine addition to my collection.
I love the StuCo peanut gallery. All three were a mood the entire sequence.
But in a more serious note, I think this chapter hinted at what's wrong with Yuu: he's a subconscious method actor, he showed that now. When he started to believe and getting emotionally into the role, he's able to say the lines perfectly and give Niko a run for her money in a fight scene (Niko's distraction notwithstanding).
Probably this also affects why he's like he is: because he's been told for years he's useless, he has come to believe it and became useless. The moment he believes he's not, I think Yuu will start to do better.