Okay, my 2 cents on this matter:
1. All you hear on the media these few days are a lot of RnB, Pop, Hip-Hop, etc. What we call the "mainstream" music. They're not too bad, but I personally wont' want to listen to it for too long.
Also, among Chinese teens, Chinese music from Taiwan also prevails
2. It hasn't changed very much, except a lot of new songs which I hear people singing badly to.
Jokes aside, more teenagers are more excited and go to a lot more concerts and buy merchandise these days. They realise that downloading the CDs would save them money, but there is no way to get merchandise or a live concert for free without missing out on something. This is especially so in concerts. Seeing it on Youtube doesn't bring the same atmosphere as a crowd would at the actual gig
3. Electrico has done it, Great Spy Experiment has done it, a few bands have done it before. It is not easy, but it can be done. But one cannot limit himself to Singapore, as the market is only so huge
4. Better ensure that you have good songs that people would listen to. People want to listen to good songs, not utter crap that sounds like you wrote, composed and recorded in one hour without much effort.
Also, if you're holding a concert, make sure that the sound system is good and that you put a good show, able to entertain the crowds.
5. I've got not much of an idea, except perhaps COMPASS.
Either way, you wouldn't need to bother too much about copyrighting until you made yourself known, until people say: "Oh, I know he/she exists. How are his/her songs like?"
That's when you might want to consider copyrighting your stuff before someone kopes it from you.
6. Perhaps it can earn you a bit of a living, but it would not be feasible in the long run. The market is way too small, mostly due to the geographical nature of our little red dot. Overseas would garner you more attention and allow you to explore more boundaries that you never expected.
Besides, look at "local talent" that made it big. JJ Lin, BY2, Tanya Chua, just to name a few. They were all exported to Taiwan first, where they made a name for themselves, before Singaporeans stood up and shouted: "What? They're Singaporeans? YAY!! Go Singapore!"