We are hoping to have a decent portfolio built in the next 5-10 years to help supplement our income and hopefully give us some more free time from our 9-5 for when we decide to start a family. 

We have even gotten to the point where our townhome development is offering new buyers a payment supplement program for 24 months just to drive sales.

Could they find a third to supplement the rent?

You used the phrase "replace our income" vs. supplement, so I am taking this to mean you intend to quit your W-2 jobs and go full time real estate once you get to the end of your plan.I am sure you realize that $10,000 / month from rents isn't like $10,000 pay check. 

I was prepared for the new property tax amount as a percentage of the sale price but I wasn't prepared for the supplemental tax invoice which is separate from escrow and I still don't fully understand how it is calculated. 

Figure out a way to supplement your real estate business until you can start earning more.

(b)Or ask your plan checker for a supplemental to change the scope of work... this way you do not go back to the beginning of the process, and you keep the plan checker that is already familiar with your situation.

And I do have enough income to supplement a negative cash flow property, up to a certain degree.My next task for myself is to research where are the most cash flow positive places in Canada.TL;DRMy goal is to invest for the long term (not flip), rent it out (long term?

We are not looking for a get-rich-quick scenario but rather using RE to help supplement retirement, eventually adding to our monthly income, and creating generational wealth for our kids. 

Hello BP Community,Airbnb Host Liability Insurance is a great start for a vacation rental owner; however, what do you look for in a supplemental STR insurance?