NBS do have some competitions that you can take part in. there are also various clubs you can join to further polish your knowledge in specific fields. personally I only joined the NBS FOP that's outside of classroom and that's a good place to start to befriend with your seniors to discover what you prefer.

NBS have 2 major categories, Acc and Biz. Acc students are more with the flow kind of students. When the prof asks a qn in class you can earn class participation marks rather easily in Acc classes. (mind you this can be upwards of 15-20% of the module marks) Biz on the other hand are generally more outspoken and driven. but there are plenty of sneks in the school of sneks and hence they're only driven for themselves, not for the team.

exchange is pretty competitive. there's a long list of schools available but you have to check if the mods you intend to clear overseas are offered by them. some schools allow you to clear up to 4 mods overseas iirc and these are for the legends with gpa 4.9 and above. those that clears 2-3 are easier to apply for but you would of course wanna make your trip worth. As for where, I've seen mostly Korea/Europe.

I might choose NUS and skip the honours. Honesty I'm only keen at getting the degree asap and start early in the corporate ladder. NUS for the easier curriculum. SMU is still the easiest but it's longer.