Re: Margin lending vs traditional loan
Be very careful with mixed use loans!
The ATO has ruled a few times with regards to mixed loans, in particular split loans, saying that there is no way to pay down non-deductible parts of the loan in preference to deductible parts. It is even more hairy if you plan to use a single standard LOC and move funds in and out for both private and investment use.
Get a separate, interest-only, LOC for investment purposes, before embarking on purchasing shares or funds!
In another matter, deductibility of a ML and LOC are based on the same premise, that is that the investment is "income-generating".
The ATO tends to allow deductibility of investments in HighlySpec.com, on the basis that there is a reasonable likelihood of future income (not purely future capital gains!). So it is prudent to maintain a dividend-paying foundation of blue chip shares for your portfolio (but this is just a good idea anyway!).
I have not seen it tested, but for example, an investment in AMP Capital's China Growth Fund (AGF on the ASX) may not be deductible, since the fund's summary states: "The objectives do not include the payment of regular income to investors." This clearly (IMHO) violates the ATO's requirement for income for tax deductibility.
Just some cautions, not advice.