The Shadhili path has been traveled and tuaght by ulama of all the four madhabs. There are no restriction on reciting hizb bahr... Although I've heard some Shuyukh say it is better to get an authorization, but not having one shouldn't stop you from reciting it. ..... So if Allah gives you tawfiq to recite it then make it one of your daily dhikrs... And insha Allah you will benefit from it...