1. All training for a licence or aircraft rating must be conducted from a licensed aerodrome. Presumably as he has never exercised his PPL privileges he will not have a SEP rating in his licence so licensed aerodrome it must be.
2. With regard to the aircraft it depends on how it is maintained. In order to conduct training it must be maintained to public transport standards; There must be an Airworthiness Review Certificate (ARC) and a certificate of maintenance release issued by an approved maintenance organisation.
The above AIC may be out of date as new EASA requirements came into force last week!