20 years ago, we used to do that all the time. I lived in Singapore for 11 years on a social visit pass. But in my case I was gone for 1 or 2 months at a time on the oil rigs & came back for 4 weeks normally, when it ran over we used to do the same thing. Those days are long gone. Now you can usually do it once or twice max but they will tell you the next time you will not be allowed back in. You almost have to fly out and back and be gone for a couple of days in order to get away with it. Eventually, that will have to stop as well. Time frame? Depending on where you are from, 2 week extension to 30 days. Some may give you the full 90 days but I'm not too sure there. It's not really a doer in the medium term - only short term. Three years? Doubt it seriously.
I don't think so, as it is not a working visa. However, subletting from somebody might be possible but again, without a contract it could be dangerous for both you and the landlord.
Without all the controls here, Singapore would have never gotten to where it is today. You cannot rapidly change directions without a large dose of Control. And I believe LKY invented the word!
