I am an Indian who studies in the US, and am planning to visit France/Italy. I've applied for, received and travelled to Schengen zone 4 times in the past (as a minor) without incident.
During my last trip, 3 years ago, I went as a school trip to Germany as a 10-day exchange program where we stayed in host families' houses. I think Germany has a rule that travellers not staying in a hotel need to register with the police - we didn't do so. There was no problem exiting the country - as I remember, the immigration officer just asked some routine questions while exiting.
So now I plan to apply via the French consulate - should I expect any problem due to not registering? What can I do?