SMU has a school called School of Economics so Econs is not a arts degree
NUS's econs is in Faculty of Arts and Social Science, so Econs becomes a arts degree (BA major in Econs)
NUS offers Statistics in both Faculty of Science and Faculty of Arts (my time, not sure about now), so Stats can be a arts or a science degree (BA major Stats or BSc major Stats)
Anything that has the word "science" in it is not really a science, e.g. social science, computer science. Economics is a social science. B.Sc. (Econs.) really doesn't make sense to me; B.Sc. should be reserved for natural sciences. That said, I believe there's no material difference when it comes to job applications, if that's what you're concerned about.
They'll probably make you read "Business Law" (whatever that means) and "Company Law". You cannot do post-grad law without a LL.B., but you can do an LL.B. if you have a B.A. (Econs.).
can do juris doctor programme (post grad law degree/requirement is any undergrad degree)