Threadjacking: YES. Especially if there’s hijinks involved with multiple characters.
4th Walling: Considering world Daria is from, she’d think it was all craziness and weird. Then she’d spout a book reference or two. Mostly acceptable with context.
Hugging: Daria isn’t the most intimate person and isn’t a fan of touch. None the less, hugs are harmless and accepted if she actually likes your character.
Kissing, Hurting, Mind Read, Killing: Ask first.