Are common people considered sinful if they follow the fatwas of a mufti who permits dealing with banks and forbids a veiled woman from advising her immodest sister?

Allah commanded the ignorant to ask the people of knowledge. It is not permissible to restrict fatwas to the official state mufti, as Muslims have only recently known this position. The ruler must choose the most knowledgeable and pious person for this position. If a person is known to follow whims and permit the forbidden, it is not permissible to refer to him. Bank interest is usury, forbidden by scholarly consensus. An ordinary Muslim is obligated to ask the most knowledgeable and pious scholars, and it is not permissible to seek out dispensations. A woman must cover her entire body with clothing that does not describe her 'awrah, and wearing trousers in front of men is a clear abomination. Whoever relies on the statements of sheikhs to permit forbidden things is deceiving himself, and Allah Almighty said: (They have taken their scholars and monks as lords besides Allah).