My super duper archetype classification and how I imagine you as a typical high school anime character

Marlyn - a mix of a chuunibyou(8 grader syndrome) and student council president,
Most likely, dresses without altering the uniform much, but of course has his piercings and some kind of bright eye-catching accessory
Emotionally unavailable oujidere, probably bullied anime-vaso in junior high school

Erika - a shy undere meganekko who probably wears a knitted cardigan, the skirt sits lower on the hips which makes it look longer, ijimerarekko

Cathie - tsungire, for sure a (shiro) kogal with slouch socks, pink accessories and hairclips

Niel - Fukou Taishitsu (bad luck), Hetare
dandere+kekkondere, probably doesn't alter his uniform much
Maybe just appears more visually clumsy and untidy, Tennen Boke

Gustavo - an otaku rokabiri zoku (greasers inspired yankii subtype), an obnoxious uzadere
Stylistic implications of uniform altering are pretty obvious
Kuishinbou, if we view this in relation to me he'd probably be me osananajimi (childhood best friend trope)