Hi, I do not think that you are legally bound, unless you have an existing agreement with the property manager.(check with the Real Estate Institute of Australia, to confirm this fact) When the agreement is up for renewl, you may decide to end the agreement. I do not know what you contract states. I would suggest you dig out your agreement and look at the terms. As the property owner you can act as the landlord, most people use a property manager to avoid contact and the hassles associated with the tenant. If you are up to liasing with the tenant directly then by all means go ahead. You probably have an emotional attachment to the property, be careful this does not cloud your judgement when it comes to dealing with specific issues. Make sure you know the ins and outs of the rental authority, what your rights are and also the rights of the tenant.
When you have fewer propertoes, it may be easy to manage yourself, but if you start expanding it is best to invest in a good property manager who will in time save you time and money.** Steve states this in the book
Go to reiq.com.au (or call The Real Estate Institute of Australia) or look up rental authority in the State that you are in, to research the topic further.
Good Luck