If one is aware that there are differences between the Maraje in the rulings that affect him, which is usually the case, then he must observe precaution. Since its not practical for many to do so, he must find the most knowledgeable from them and follow him.
It is permissible to look at the picture without sexual desire. But if looking at her is shameful for her, as she observes the hijab, or is respected in the society, and similar reasons, it is prohibited to look at the photograph even without lust.
It is not allowed to take mortgage loans with interest from private banks. It is permissible from government banks without the intention of borrowing, but the individual collects the funds on behalf of his Eminence (may Allah prolong his life) and then takes ownership of them after that. Interest is then paid just like paying taxes to the government.