What’s your philosophy about dealing with confidential information?

Treat all confidential material on a "need to know" basis. Only involve those directly concerned with the confidential material!

Given that I understand your question correctly: Confidential information is exactly what it is – Confidential

Unless the company will be affected by the outcome of the information I personally think it should be reported on the other hand if it concerns individuals I recommend displaying integrity by keeping info confidential

My philosophy is that all these matters are private and concerning someone else. In any case we don't reveal them, regardeless the good or bad work relationship. 

To me as the word sounds confidential it has to be confidential because any leakage of confidential information may land in to the hands of the competitors which is a threat and may easily lead to the collapse of the company or may affect it in one way or the other so anything confidential has to remain confidential,period.