The answer to the original question is 'Yes'. Under JAR/EASA, you can fly as PIC on a private flight in any aircraft on a PPL (i.e. with a Class 2 medical), provided that you hold the appropriate class or type rating. However, to obtain a type rating on a multi-pilot aircraft you must have passed the ATPL theoretical knowledge exams (but not necessarily hold the licence) and hold an instrument rating.