contact the Adelaide office of either the Institute of Chartered Accounts in Australia or CPA Australia, explain to them the reason(s) for your call and they should be able to give you some practioners' names to contact.
your comment : ".. making a profit and capital involved seem to be secondary."
your view about "making a profit .. seem to be secondary" is wrong. It is a primary objective for starting a business, any sort of business, but it does not mean you must make a profit in your first year of operaions.
Yes, as a general rule, the way you go about conducting your "share trading business" is important, to justify your claim that is is a business.
