hiiii dreamcatcher

yes it is like what u said; from what i know they don't ask for ppr from visa exempt countries; copr is enough to land and for u copr + csq (original) and the valid passport of course
also to avoid headache there u would need to fill in from before a list with ur goods (categories, not really one by one; but if u bring in fency electronics for example then it's better to describe them, write any serial number for the computer, laptop, iGadgets, etc); like this u will b exempted from any duty; also if u have any goods which will follow u, then u'll need the "goods to follow list" as well which will b stamped on the day u landed (again this will help not pay any duty for those)
i find it really stupid that the travel agent won't book u a one-way trip; i never heard of that before

canada is not a country where ppl started to immigrate yesterday, there r soo many pr's landing every day and they all have one way tickets or maybe they don't believe anyone from Australia wants to immigrate there :

anyway either find another travel agency or try to book online
cheers