Of course she needs to mold chakra, that's a given.
Yeah, no Lol she does need to be conscious when sensing, as shown when she needed to go in hiding an concentrate in order to locate Danzo.
When I sense unconsciously I mean she can sense or pick up things instantly & without any mental commamds. XD
For instance, Karin was kilometers away from Kiba and Naruto.
She wasn't objectively trying to locate them nor was she keeping tabs on their movements.
But then minute they entered her range she picked them up without any mental or conscious effort or maneuvering any chakra.
A Hyuga wouldn't have been able to do that without conscious effort and specific concetration.
Karin solos.
Speed. for example, Karin would sense the enemy but what's the point if this enemy evades her? As for Naruto, he would be able to sense the enemy and track the enemy down with his god like speed. Speed is a variable in tracking, which goes hand in hand with sensing.
Karen's speed was never implemented in the manga or shown as a strength of hers. The only thing that's above average is her sensing(which is OP af). Her combat and speed may even be genin level or lower for all we know.
But this thread isn't about speed its about sensory.