Why do people think bio is hard. Seriously, you must not be that clever. Bio is a fucking fantastic class to boost your OP (if you're good at it) because so many dumb people take it because they want to take a science. Your high score + their low score = fucking high OP. That's why I'm taking it (and I'm doing a bach. of science when I'm older, and I guess doing a science would be appropriate).
Chief financial officer is definitely more stable and will be a good platform for better things. Sharebroking is a really hit and miss occupation. If you really want some good cash and don't mind putting in a lot of hours and work then you should consider going down a path to become an M&A Analyst (merging and acquisitions). Juniors earn around 100K a year with seniors (5+ years exp) earn in excess of 300K, keep in mind though that their average working week is around 70+ hours. I think financial officer is a more balanced position to be seeking.