It's an agent's Australian tourist visa. What will the visa officer ask by phone? Will he call the company to ask for my detailed information? Is the refusal rate high?

Whether the materials are fully prepared is very important. I'll ask you the reason and itinerary for going to Australia. It is also possible to call the company to ask about the authenticity of your materials, and usually call the numbers of other departments of the company instead of the company number you left. The first signing meeting is strict, but as long as the materials are true, the refusal rate in Australia is not high.