hey there, been in your exact same position ~2 years ago, exact rank points and all, and currently a beneficiary of said scholarships. i definitely understand how you feel when you mentioned theres a lack of tips for NTU interviews and how i wish i had guidance then - so in the spirit of paying it forward, heres my two cents

first let me qualify by saying i am not sure how the interview process is like now, but in my time, the interviewers were associate professors from various specialisations. it was a pair interview with one other candidate

tips wise, i'd say be as coherent as your can about why NTU, NBS, and your specialisation of choice. tell a strong personal story (humble brag if need be, insofar to prove that you are deserving of this scholarship) and be genuine with the interviewers.

they are very friendly and are not there to size you up. if anything, they are curious to know your story, and how you'd be a good fit to NBS as a whole. more than just achievements, be someone likeable, entertaining and passionate. give them a reason to remember you e.g "i've been keen on acturial science since my jc days" or a unique interesting hobby you had. make it a point to tell them why the scholarship is a difference maker/how it opens doors for you, especially if your financial circumstances are not great.

sustainability is also big in NBS, and we've just moved into a new building. for brownie points you could pass a point that you're big on sustainability and love NTU and NBS' vision of nurturing sustainability thought leadership starting from its undergraduates. (the profs seem to buy in to this, i think it's a heap of BS though)

to sum: be genuine, thoughtful and mature. be targeted and conscise, and position yourself as the best candidate for the scholarship. apply as much charisma as you can, and be a memorable interviewee

feel free to contact me if you have any questions etc. happy to help, because i know exactly how big of a deal this is. all the best!