Duquan and high school
So, during the season 4 finale, Dukie is on his way to attending his first day of high school and gets cold feet, the final straw being when 3 guys walk past him and laugh. While I get that at the time it was nerve-wracking, none of his friends from middle school would be there, the one teacher who'd shown faith in him wouldn't be there etc, I don't understand why he didn't try going back at some point after we're shown this.
It was clear even at this point, never mind season 5, that the corner life wasn't for him. Once he started living with Michael, he was a lot more presentable (neater hair, better fitting and cleaner clothes etc), and while his skinny build and his soft nature would have made him a target for bullies, he may also have met another Prezbo, or found a group or club where he did fit in, just generally found his niche there. And it's not like he wasn't getting at least disrespected and often bullied every day on the corners anyway.
Long story short, he'd have been better suited to school than he was for the streets so it's a pity he missed out.