I will address two of the three, because I raised those exact same points.
The answer lies, in part, in what this committee decides. I have just ruled that the motion is in order. The committee, during the debate, is free to set the scope on any report.
I know there has been reference informally to the 2004 review of the then governor general's expenditures on another trip that drew headlines. I would note that that motion was substantially different from this one. That talked about reviewing the estimates. This motion talks about reviewing the expenditures, which I think is an important point of differentiation.
It is possible that the Speaker could rule it out of order, if this committee takes allowances beyond its mandate. I don't believe this motion does that.
Number two is a question that I also asked. Parliament does not have the power to order the Governor General to appear. However, the wording in this motion is “invite”, which is different.
Your third question was whether this committee had ever heard from the Governor General's office.