You have very few options for living (there are no suburbs or neighboring towns.) You either hangout with the tourists and transients merchants in the southern tip of Kowloon, and get nickled and dimed by merchants. Or you can suit up and live somewhere "decent", HK Island side and live the spender life I described above. Or you can live in the fringes of HK, in the New Territories, Lantau Island or some other no-man's land.
The first thing anybody will ask you is "where do you live". The location of your office is of prime importance. You will see most HK companies have photos of their office buildings, that's because there are a ton of paper businesses there and people go overboard to establish their solvency, if not their legitimacy. Everyone has a business card too.
The business registration requirement for HK is essentially $1k. Their laws are so flexible as to be an informality. If you have the money, Hong Kong will accommodate all your wishes. You just pay any accountant or lawyer anywhere in Tsim Tsa Tsui and you get a folder the same day. Then you take $5k to HSBC and open a business account. You're done. You ring up your favorite credit-card processor and get an ACH.