Interesting info. Guessing it's the same in Australia but here in the USSA tenants (and everyone else) are lawsuit-happy so the best advice I ever received is to make sure each rental property is owned by a separate Limited Liability Company (LLC). Not sure what the equivalent would be in Australia.
The main problem with this is it would probably change the tax deductions you get and also it would be more difficult to get the loan for the rental properties.
RE: How to pay 0% tax in Australia, legally without owning a business.