Marc
The name "Mark" in French is spelled as "Marc."
The correct spelling of the French name is "Francois."
Jocelyn in French is also pronounced "Jocelyn." It is a unisex name and does not have a different spelling or pronunciation in French.
The usual spelling for Luke in French is 'Luc'.
Luc is the French spelling for Luke
The French spelling for Kyriakos is 'Cyriaque'.
Ralph has the same spelling in French that it does in English.
The only correct plural for French is French. "Frenches", as you say, or 'Frenchies' is a derogatory slang term.
'Brigitte' is the French spelling for the first name 'Bridget'.
Paul is the French spelling for Pablo.
Adrienne is the French spelling of the first name Adriana.
Ariane is a French name. Another spelling is Arianne.