Every other 125 in the European JAA world is required to have a 2 pilot crew
What makes the Dominie so different? Are there any other twin turbojet transport type aircraft flying with only one pilot?
But you can't generally pick and choose the rules you choose to obey and the ones you won't. To operate it under JAA should captain and co should have JAA licences? Should the aircraft be maintained in accordance with the regime? It might not stop there, even.