Aussies are a common sight here in Colorado and while aggression is in their DNA, they respond well to training and constant attention from their masters. There are also breeding lines that are perfectly suited for domestic life. It's not too late to inquire about yours. It will ease your mind and give you an idea of what to expect.
As for intelligence, as a group, Aus cattle dogs, blue heelers, Aus shepherds, and border collies, when grown and well trained, are estimated to have the intelligence (I.Q., understanding, or cognition, depending on how you choose to define it) of a six-year-old child.
Have fun with your new friend! Buon Natale, Charlie!
Zieg
P.S., the best packaged foods are grain-free. If you are making his food from scratch, which is an excellent practice, I would avoid grains in Charlie's diet. Rice is OK, but like with people, brown rice is better. White rice can bind them up in the gut, which is good for the occasional bout of diarrhea. Stay away from corn (maize) altogether. Limit wheat products and pasta to an occasional treat. AND NEVER GRAPES AND RAISINS! THEY ARE DEADLY! Of course, you know about chocolate. Be careful, too, because Charlie will be convinced that he needs a shoe or two in his diet.
My wife says your recipe for Charlie is very good but to exchange the pasta with brown rice. Our greyhounds want to meet Charlie!
Z