If you want the job done right, then yes: grinding, filling, sanding, priming, and spraying are your best option. There are alternatives out there. Duplicolor makes color matched kits which allows you to paint in the smaller chips (it has an abrasive, color paint brush, then a clear coat to go over the top). I haven't used them, but the product looks like a winner. I'm not sure it's going to work for the larger chips, though. Your problem, however, may be the rust. You cannot just lay over rust with paint and expect it to last.
I found this video on YouTube. It seems fairly comprehensive as to minor chip repair. He goes over all of the basics up to the painting of the vehicle.
This guys gives a pretty good presentation on how to do all of this with rattle cans (spray cans). Two things I would not do which you see in the video is: don't do this on a windy day. You'll make a mess of things. Second, do not use a scratchbrite pad. They can cause you all kinds of issues with paint adhesion and orange peal effect. He also does not explain to you about how to do use the buffing machine very well. If you are not careful, you can cut right on through your brand new paint and you'll have to do it all over again. Use the machine lightly and be careful near the edges.
You can go to a paint store which sells automotive paints and have them make you a can of color matched spray paint for your vehicle. I don't know what the local laws are in Australia, but they'll be able to tell you at the store.
You shouldn't be afraid of doing this yourself. It can easily be done with spray cans and have a professional outcome. Two big things: be patient; be clean. Both will have a large outcome on how everything will turn out.