>Does he have any gap moe traits or hobbies?
He loves sweets to infinity, just like me.
>What's his place in his source material, how does he effect the plot and the other characters?
At firstly he's that sugary sweet boy, nobody can say no to him. But later you find out that he's working for the bad guys who are soldiers and fight against the XYZ Dimension. He switched the sides and let his new friends alone and betrayed them. Later in the show, he rescued one of his friends and realized that it is totally bullshit to serve the academia anymore and said, it is the first time he ever had friends and he want to protect them. So he's a good boy now.
>Does he have any close friends? If he does, what is their friendship like and how do they treat eachother?
He has 2 really close friends, Yuzu and Yuya. At first Yuya was really annoyed because Sora followed him everywhere, to learn how to pendulum summon. Later Sora teaches Yuzu how to Fusion summon, because she wanted to be stronger to protect them all. There was a Time where Sora betrayed his best and only friends, but came back to them, when Yuzu talked to him, that he is one of her closest friends. Yeah so now there are a cute little bunch together who cheering them up one another.