Yea, I think taking up some business related modules in non-core is helpful to an extent. If you are studying in NUS FASS, the system allows you to take a considerable proportion of modules outside your faculty. You could structure ~1/3 of them in business related stuff.

As for coding, you can take up in your free time, but I doubt it's going to be a game changer during interviews. Advanced coding skills are in high demand, but those require CompSc or similar depth. Fiddling around VBA or some form of rudimentary C variant language IMO is not of much use in most non-programming jobs.

If you aspire to join ministries/stat boards, focus on your GPA and CCA related stuff. They are really into this sort of thing from my experience (doesn't make much sense IMO, but that's the game).

If you want to join those top MNCs like Microsoft, Unilever, Shell, Google, P&G etc. then getting a few internships or even temping in similar good MNCs is very important for both networking and CV branding. The experience will also help you understand the culture of these organizations and the things they look out for. I know many grads without this exp fail during their first round interviews because they simply over rely on selling their technical competencies and academic scores which is not what these employers are looking for.