1) If I follow a marjaa and within my self I find that some of his rulings are not logical, and I find the rulings of another marjaa more logical, may I change marjaa?

2) If I follow a marjaa and I find certain rulings not logical, can I disobey them?

3) If I feel a certain marjaa is more knowledgeable based on feelings but logically another marjaa is more logical (which makes him more knowledgeable), may I change?

1) One’s logic is not the measure of the knowledge of scholars. If you are an expert, your opinion counts. You cannot change, unless you are changing from the less knowledgeable to the more knowledgeable.

2) If you are a mujtahed and have made your own research and concluded against the one you are following it is OK otherwise you are essentially disobeying God

3) It is not about how you feel rather, it is a subject that experts confirm through their knowledge