You can exchange money at the Louis hotels reception.There are 3 hotels together on Mavratzis beach. Excellent place to stay.
Although not as good as Vasilikos, there is a large,good beach in Laganas, but obviously a lot busier than the ones in Vassilikos. Wouldn't recommend the mopeds after seeing the queues outside the pharmacies, but you can get buses in and taxis back reasonably. But if it is nightlife and a good beach your after, try Tsilivi.