@Kelly LaneHouse hacking is a viable strategy for building wealth through appreciation, even in high-priced markets.

I would suggest the only safe "minimal down" strategy is when you're doing the 1-a-year plan.

The best strategies will be tailored to your specific situation. 

How consistently has it show that it can be profitable. 

It's a strategy that has proven effective time and again.Five years is a solid timeframe to account for market fluctuations and ensure profitable sales.

When managing the "security" this mortgage is a part of they probably have a strategy for how to manage that is based on keeping a stable known risk for the security.

You should call a couple local banks to discuss the types of investments you may be looking for.Alternatively, a great strategy for someone just starting out is House Hacking.

Many buyers/investors are using this strategy to invest in real estate

The appraised value seems low and I am trying to understand the best strategy to challenge this value and the cost / benefit of going through the condemnation process. 

It is my understanding that the company works out the tenant billing rates based on your master utility bill to keep it consistent and fair.So, the technology exists BUT is it legal in Maine to bill the tenants in this way?