If I open a bookstore, it's gonna be like this: Wedged into the tiny fissure of 43 Carmine Street, cheek by jowl with a restaurant and a deli on a typical Village commercial block, Rockit Scientist is in its sixth year of existence. A stack of milk crates near the entrance hold $2 bargain CD's. A forlorn houseplant looks for sun in the corner. An array of magazines, ranging from Q to Ugly Things, is spread across the counter. A sign advertises: "Established Manhattan-based British Invasion band needs 35+ bassist. No Egos!" No more than two customers can stand comfortably abreast.