No honorific is required when addressing the former chairman of a committee.
'Mister Charman,' or 'Madam Chairman' or "Sir' or 'Ma'am.'
Senator Doe,
addressing attorney and wife
vmrs
The proper salutation for a retired General is "General (Retired)" or "General Smith (Retired)" when addressing them formally.
I believe in a report you should say for an example the president Mr. Barack Obama.
The friendly letter has a proper heading. Use the salutation, Dear, followed by the first name of the person you are addressing.
The proper salutation for a psychologist is "Dr." if they hold a doctoral degree (PhD or PsyD) or "Mr." or "Ms." if they do not have a doctoral degree. It is always best to refer to them based on their level of education and preference.
The proper salutation for a probate judge is "The Honorable [Judge's Full Name]."
What is the proper salutation for a register of wills, e.g. Honorable John White?
It should not matter what ethnicity the person is when you are addressing them either formally or informally. Mr. and Mrs./Ms. should be used if you are writing to the person in English.