Difference of opinion that opposes the Quraan and Hadith

It's very important to avoid fitna.

When there is an isolated opinion which contradicts the general opinion, can we say that there is a difference of opinion/divergence?

Example, Pharaoh died a disbeliever. If there is a scholar who emits the possibility that he did not die as a disbeliever, is it possible to invoke the expression difference of opinion/divergence?

In the case of Abu Talib, he died a disbeliever. If there is a person who invokes the possibility that he was saved, that his repentance was accepted, is it permissible to say that there is a difference of opinion/divergence?

Should the book of a scholar be brought to the general mass, he has the right to write this in his personal capacity for his own reflection, but is it right to attribute to him a difference of opinion/divergence?

Could he have done this for people of the same caliber as him, that is, a book addressed to other scholars and not to the general mass of ignorant people? For a person who is not scholar who does not even have the basics a student is allowed to quote his isolated opinions and to invoke a difference of opinion/divergence, my question is can you give us a detailed clarification on this on the rules business and not to do?