Yes

Yes, you can. You can also rent it one way, i.e. return U-Haul at Toronto. Of course, you will pay.

You should bring the list of goods with the seal of Canada Customs when you firstly entered into Canada. Be prepared for questions like if you have anything beyond the range of that list.

If this is your first time to enter Canada, just put everything on and even more which you may bring to Canada later.

Usually it will be fine. They may take a quick a look and let you know. However, if you have big things like a new car but it is not on the list, you may need to pay the tax.