Incidentally, I don’t mean that in a snarky way. It’s a simple statement of fact. Music publishing isn’t all that profitable even for the big houses these days, and I wouldn’t recommend setting up even as a piano arranger if income is mostly what you’re looking for.
As for the copyright issues, if you’re in Indonesia (I think that’s what you said; apologies if I’ve got that wrong) or anywhere in the Pacific Basin/Asia, American copyright law doesn’t apply.