Hong Kong Utilities
Depending on where you are you may have a different provider, CLP or Hong Kong Electric. You will need to get them to come and read your metre or connect the service, sign and chop your contract and pay a deposit, which is repayable after your final meter reading.
Well depending on what type of business you have, but basically the same will apply as your electricity provider. Any equipment will be subject to safety and compliance checks.
There are a number of choices of providers, the majority offering deals. You could spend hours deciding on whose contract you're going to sign depending on the breakdown of your possible call profile. If I have any advise is get someone local to sort it out and go through the negotiation otherwise it will drive you nuts.
Same as electricity that you will be required to pay a deposit, repayable when you leave. Everyone is on a metre and yes you can drink it, but most people use bottled water out of preference. Toilets are flushed with sea water, all very environmentally friendly.
Bills will carry a late settlement surcharge, the bill is due when it was issued and you will be disconnected if you forget. Reconnection does take time and there will be a charge.