As far as it predicting high on revenue, that's obviously the biggest risk and I'd be concerned about that as well when getting into a new market as a short term rental investor. 

Trying to nail in a location that will have high volume of renters.

I would highly recommend working with a broker that really understands the nuances of this style of loan as each lender has different credit requirements, leverages, and ownership requirements. 

Great time to expand values are high, rates are going to start to fall again in the next 60-90 days.

The second property will be purchased with a mortgage (you can determine how high or low the leverage will be by adjusting the proceeds you use or the price point of the 2nd replacement).You are adding some measured debt at a level that your dad can be comfortable with. 

If you're looking for more connections, I would highly recommend attending some local real estate meetups in the cape cod area.

MICs generally charge a lot in points and have high rates, and typically won't lend above 75%-80% of purchase.Some brokers will also have access to private individuals who are willing to lend, which can be more flexible.

Accountant "view only" access to your bank so they can pull statements and check/deposit images without paying themselves.

Ouch... 75% set up fee sounds really high.

Due to the rising cost of buying a home or paying high-cost rent.