If they want the files or make any other changes to your kind gesture, charge them for a full video shooting editing included, as for the footage, the shots that they are not in it, you can use it for what ever you want b-rolls ect...(exemption if they pay you dont use those shots afterwards) but if they are in it i wouldn't use those shots, as if they own the footage they dont . next time ask more questions and to everyone that is involve,
or else it can go bad pretty quick