On application for the IR you need 50 hours PIC on cross country fights. The PPL course includes a minimum of 5 hours PIC X-Ctry so maybe you only need 45!
If the instructor acts as an instructor and is authorised as the PIC in the Technical Log you must log it as Dual. If the Instructor is a passenger (unpaid) then he may be able to give you some free advice whilst you operate as PIC. Do instructors work for nothing?
Interpretation of the rules in France may differ slightly from the UK.