It would be “tú estás pasando por la aduana” because you are using the present progressive so your would have to do estar conjugated + verb ending with ando/iendo
Just look up the book in spanish. type "Libro de piratas del caribe y el mapa secreto" on google and i'm sure the whole book will come up just gotta browse all the way to the 4th chapter.
I believed that people have an innate ability to do good, and that evil is the product of a negative environment or lack of education, not an evil nature