1st off- Kudos for your enthusiasm to tackle a difficult problem; adopting new materials and building science understanding on really old structures.Success levels for energy retrofitting will be directly tied to the level of "gutting" you do to the old house, especially trying to add a vapor design and passive ventilation retrofit. 

Per this NY Times article, the average American knows around 600 people.https://www.nytimes.com/2013/02/19/science/the-average-american-knows-how-many-people.html#:~:text=The%20average%20American%20knows%20about,do%20you%20know%20named%20Kevin%3FPer the US Census Bureau, the average American moves 11.7 time in their life, which based upon an approximate lifespan of 84 years, works out to be about every 7 years.https://www.census.gov/topics/population/migration/guidance/calculating-migration-expectancy.html#:~:text=Using%202007%20ACS%20data%2C%20it,one%20move%20per%20single%20yearSo, if the average American knows 600 people and they each move about every 7 years, that means that the average American knows around 85 people that move in any given year.How many of those moves do you want to be involved in?

Their data science crew determined it was a glitch on their end and apologized. 

It's not an exact science.

I think its a bit of both art and science, as well as availability. 

Finding off-market deals is part art and part science, but basically be prepared to knock on doors, advertise, or call a lot of people. 

This isn't rocket science and could have been done many years ago.

Be careful of someone that wants to "partner" with you and ask you to use your credit.Can be a good idea, but only if serious partnership agreement created by your attorney (not theirs).You can also start building your network to find opportunities to refer out and learn from.Per this NY Times article, the average American knows around 600 people.https://www.nytimes.com/2013/02/19/science/the-average-american-knows-how-many-people.html#:~:text=The%20average%20American%20knows%20about,do%20you%20know%20named%20Kevin%3FPer the US Census Bureau, the average American moves 11.7 time in their life, which based upon an approximate lifespan of 84 years, works out to be about every 7 years.https://www.census.gov/topics/population/migration/guidance/calculating-migration-expectancy.html#:~:text=Using%202007%20ACS%20data%2C%20it,one%20move%20per%20single%20yearSo, if the average American knows 600 people and they each move about every 7 years, that means that the average American knows around 85 people that move in any given year.How many of those moves do you want to be involved in?

But this is not rocket science, and there are not "a lot of rules".

Johnny clearly has no clue about taxes and considers them some sort of a video game moving fictional characters through fictional obstacles.