I understand that when praying for a sick person, whether privately or in a mishaberach following the Torah reading, one should omit honorifics; e.g. not to use "HaRav" when praying for a rabbi, or not inserting "haKohen" or "haLevi" in the name for a kohen or levi. For example, just last night, our rav had us pray for an ill levi without mentioning his tribal status when giving us his name. Many people I know, however, don't know this. What is the source and reasoning for excluding the honorific, and are there any contrary opinions? Is including honorifics wrong?
אדם שמתפלל על אביו אם הוא חולה לא יאמר תרפא אבא מארי או לאדוני אבא רפא
One who is praying for his sick father should not say "Heal my father my master" or "To my master my father heal"
See continuation there, where he brings Elisha not referring to Eliyahu as his master as an example - not just father/son.
Birkei Yosef Yoreh De'ah 242 (explaining Sefer Chasidim1):
אין גבהות לפני המקום
There is no stature (lit. highness) before Hashem
It is inappropriate to mention someone else's stature when speaking to Hashem, as everyone is nothing compared to His greatness.
1Birkei Yosef seems that he is quoting Sefer Chasidim, but I did not find those words in our text of Sefer Chasidim.