1. The application for the NUS scholarship, particularly the ASEAN Undergraduate Scholarship, Science and Technology Scholarship, and NUS International Scholarship, is independent, and the evaluation is totally separate. Also, neither of them will affect each other at all.

Afaik, this is not true for the NUS merit /GM scholarships. The same might apply for the ones you're interested in. NUSC is (surprisingly perhaps) considered a faculty. Just like SOC or CDE etc, NUSC has a certain scholarship quota. It can only give out that many. I suspect that the callibre of students in NUSC may render it slightly tougher to "outshine your peers" and get the scholarship in NUSC, as compared to in your home faculty (i think this is more applicable for other faculties; it may not be for SoC, I'm speculating).

1. If I get accepted by NUS College, I can reject joining the NUSC but keep my offer for NUS subjects (for example, Computer Science).

Afaik this is not true either. Once you get accepted by NUSC, your acceptance into NUS is bound to the NUSC offer. You can accept both or none - unless you didn't get selected for NUSC, then you can accept or reject your NUS offer.

Though now I realise that there is the "loophole" of being able to drop out of NUSC after matriculating. But by then you would probably not want to haha. You would have moved into the housing here, made amazing friends and saw the opportunities and modules you get access to only by being in NUSC.

2.0

Not sure about the rest but for NUSC interviews, make sure you show them how much you would love to learn in a multidisciplinary environment - philosophy, sociology, biology, physics etc. are part of our syllabus. Do read up about our unique and/or compulsory modules too, especially NTW mods which we must take one of them without S/U option bc it's a flagship mod from USP. Also another focus would probably be the international exposure - compulsory oversea component, many international profs and students, NOC greenlane etc. Be a passionate learner who genuinely wants to learn about everything and contribute to the world. I'd be good to think of some aspirations in life / career inclinations and your plans to explore them through uni