Cheaper reasonable hotels near to the downtown area of orchard road/raffles can be found on the serangoon road around the area called little India.

Food is varied, cheap and easily available throughout the island.

Travel via MRT/buses is convienient cheap and they reach most places. Taxis are readily available but are expensive.

From airport you can go to city via MRT, bus or taxi. Bus No. 36 goes to the suntec convention center in the heart of the city from the airport basement at T2.

Locals speak thickly accentuated english called Singlish. It will take you a bit of time to get the hang of it.

It is very safe to even walk around at night though basic precautions should be taken. Bars of different flavors are aplenty.

Regarding places to visit...that you can easily find out by doing some search on the internet.