You look good for Arizona State and strong for Buffalo but slightly older than the rest of the class. I can't weigh in on Singapore because I've never worked on that school's applications.
So the numbers are in your favor, but now, to really maximize your chances, I recommend that you fly out to these schools and visit them in person, officially. Do a day-long visit, talk to the admissions committee, sit in on a class, get to know some students. This will really help you a lot, because it will convince the admissions people of your commitment. Most applicants with your strong credentials don't take the time to do this, especially when coming in from overseas, so showing up in person and getting some face-time with the adcom will give you a huge competitive advantage.

Good luck!
Margaret Strother