Yes, everything ourselves. I've been to agents before and never got deals as good as I could get myself online. Although the exception last trip was 2 out of about 10 hotels, so I booked just those hotels through the agent.
Transfers, I do myself.
This is my ex-agent perspective: contrary to what they would like you to believe they are not experts at every area, they might know a handful of destinations well, the rest they are flying almost as blind as you (almost, because they have others around them to help them fill in the blanks... plus what they have picked up as they went along) So when you walk into an agency and ask for a quote, for the most part they will send your entire booking to the wholesalers who will quote it. The wholesalers have inspected most of the hotels and negotiated good bulk rates at them.
No-one at all will be spending any time checking the details of this hotel and that hotel to see which one is better for you. Or this transfer and that transfer to see which one saves you 15 minutes. They will look at the basics of your requirements and suggest a hotel that they know that will fit your criteria and the transfer company they always use. Now if you are going to Fiji or Anaheim, likely you will get pretty much what you want because they have more knowledge and options in those areas. But the further you go off the beaten track, the less they know, and that includes the wholesalers.
When we flew to Seattle and then did a Washington road trip last trip, the agents prices for the hotel we used were almost double what we paid and they knew nothing about the motels etc in the little towns, all they could suggest was a motel pass which would have been more painful than useful. The rental car prices they gave me were hundreds more than what I got myself quoting online direct with
Avis and Thrifty.
Having said all of that, all the places you are going are fairly common places for Aussies to go, and the agents and wholesalers should have a reasonable number of well priced hotels at them. As to whether you can get cheaper yourself online, well I'd say the chances are pretty good. There's nothing to stop you getting a quote from the agent but ask them to itemise the costs so you can just take bits of their quotes if you want.
The way I see it there are 3 reasons to use an agent:
1/ you don't have time to do it yourself, because it's definitely lots more time consuming than using an agent
2/ you don't have the confidence to do it yourself
3/ you don't much care about the details and are happy to let someone else handle them.