Hi. I am going to Shenzhen sometime in April. but I plan to have one day trip to Macau. pls advised me on:-

1) How to go to Macau from Hong Kong international airport? How much is the fare?
2) Is it better to go Macau from HKIA first or from Shenzhen (LuoHo) to Macau?
3) What are the 'must see' places in Macau?
4) Shopping in Macau? are they very cheap?
5) pls advised on the hotel as well. 3-star hotel will be fine.
5) What currency are they using in Macau? is it RMB?