With that spread of subjects you can go on to do pretty much whatever you want. IMO, business studies is a waste of a qualification and I don't think an economics qualification is required at that age to go into a financial field.
Business is much more useful than sciences (and I was always good at sciences).
I wouldn't say so. You don't need to be qualified to start up a business. You do need to be qualified if you want to go into any sort of scientific field whether it's medicine or pharmaceuticals or what have you. No contest, IMO.