Hey there oceanguy, saw your later posts. Actually if finance is really a problem to get into med school, then i would think that it might be prudent, to have a backup plan, which i'm sure you probably have. But yea, if all else fails, you could always do a BSc in NUS first, try to give it your best shot and perhaps try your go at duke NUS (I know it's really tough to get in, but i think if you give it your best shot, it'll be good). Doing a BSc with MCAT after that might seem like an extra hurdle, but i guess there's loads that you could do as well while doing a BSc in NUS (research projects, etc.). Being Singaporean, loans for entering into any local institution would always be readily available to you.
About defering, think it shouldn't be too much of a problem, just have to make a few calls to Student affairs, know some people who defered their offer.
Don't stop dreaming. But always keep a foot on the soil still while planning.