You will access all places of interest in Reunion without worrying about the traffic conditions. It is a pleasure to handle the curves of the island's mountain roads, all the way down to the coastal road.
To rent a motorbike over 125 cm³, you must have a valid motorcycle A license. 125 cm³ motorcycles can be driven by holders of a "Brevet de Sécurité routière" (BSR) or a A1 driver's license. Foreign driving licenses are often accepted, but you should make sure with the renter. Be aware that renters do not usually offer a comprehensive insurance for rented motorcycles. Instead, a damage deposit is requested on delivery, not cashed, and given back on return of the bike.
On a scooter, you'll be able to tour around your place of accomodation. It is, for example, very pleasant to travel on a scooter in the beach area in the west ! On the other hand, this way of travelling is not recommended for long journeys, in the mountains or the cirques.
To rent a 50 cm³ scooter, no license is required. From 50 to 125 cm³, a BSR or a A1 driver's license is sufficient. Beyond 125 cm³, it is necessary to have a motorcycle license.