So the plan is this:Spouse can do soft landing and then can go back. It is not necessary for spouse to be in Canada with you. Spouse after soft landing can come back anytime later, even as later as 2 years. I would suggest to include spouse.
Once I get my PR, my spouse will come as a visitor (on a travel visa) with me for 2-3 weeks and then she will leave. In this case would you still strongly recommend getting the marriage certificate?