Most of the islands I’ve been to use the European type sockets, so the adaptors you might use on the Continent will do. If you do happen to find yourself without an adaptor most islands will have one for sale in the island shop.
US Dollars are the preferred currency. You will not find the local stuff (Maldivian Rufiyaa) in use on the resort islands at all. You will not find anywhere to obtain them and none of the tourist islands accepts them. If you are going AI you will not need any cash apart from a few dollars to tip your room boy, waiter and luggage porters. Any extras you buy will be charged to your room (you cannot pay in cash) and you can settle your bill by credit card at the end of your stay.
I haven’t a clue what rojash is talking about. I’ve been to the Maldives more than a dozen times and have never encountered any problems whatsoever. Crime on the resort islands is virtually non-existant. There are some political tensions in parts of the country but you should bear in mind that, unless you go on an excursion, the only locals you will encounter will be the staff who work on your island. There will be no other people on your island apart from your fellow visitors.
Have a good time!