I went to lumber liquidators and requested that I can have a personal commercial account.

We've come to realize that the Boston market is too tough and the numbers don't make sense (to even house hack), so just recently, we decided to hone in on Plymouth, MA... with the idea that it could be a good tertiary market to do furnished rentals (thinking short-term/AirBnB in the summer, and mid-term in the offseasons).

Yes, the spring/summer season sees demand ramp up, but that doesn't mean a house listed in December won't sell.If you buy in October/November, chances are you won't be listing until January, anyways.If I had a house completed on, say, December 15th, I would likely sit on it through the holiday season before taking it to market, but I would talk to realtors.  

For a $100k house, we can agree on payment terms and pay the seller $120k over time.

We formed an LLC to flip houses - Partnership is 50/50.  

I constantly hear people online (Social media) talking about getting an FHA loan and house hacking a 1-4 Unit property.

Nick,Why can't you buy the house as a "rental" and then when you are not able to rent it out easily and then you can move into the main house and rent out the ADU. 

Collectively between our personal residence mortgage and rental mortgage we are at a 50% LTV ratio.  

My vision is to invest in coliving and section 8 housing.

Calgary is going through a bit of a boom right now with house prices 10% higher than they were last year, everyones trying to flock from Toronto or Vancouver and find value there.