I'd be careful about predicting growth rates . Markets are probably topping out depending on where you are so even though the average capital growth might be X , you could have a 5 year period of no growth and then a spurt . I believe parts of Sydney have done this a couple of times in the last couple of decades .
I assume your planning to invest in one of the bigger Australian cities . That gives greater certainty of consistant growth as compared to country areas with smaller employment bases . Particularly over the time period you're talking about . E.g. The projections for Melbourne is that it will overtake Sydney as Australia's biggest city in a couple of decades .
Try and buy properties with a bit extra something . Obviously you want to buy well located stuff . Close to transport and services . If a property comes up beside one you already own ( if the timings right ) , buy it . It gives you a development aspect down the track . There are lots of examples now where a few neighbours have got together and sold their properties as a lot to a developer . They achieved much higher prices than they would have if they'd sold separately .
Don't consolidate your loans . These days it's probably just as cheap to have them separate and just as convenient thanks to online banking and the like . If the loans are separate it will give you greater flexibility when you're trying to maximise your equity .
