You have three separate categories here: lending, legal, and tax.For the lending side, the lender has a clause in the loan documents in 99.9% of loans that allows them to "call" the loan if their is a change in ownership of the property.

It allows buyers to qualify with different guidelines than what a conforming loan would require.

You may want to consider seeking a property manager and legal assistance.

If you work with a local community bank or credit union or some lender that doesn't sell to Fannie/Freddie in the secondary market, their guidelines and pricing could be different on this matter. 

This is my first home purchase and the first agent, can i legally ditch my agent?

You mentioned that I will potentially owe 'less than 80%' based on the work being subpar - Legally, how would this number be decided?

I would not trust AI with anything really important, like writing legal documents or designing a new house.

The Scope Of Work should not change just because you get permits to do the project legally.

What are the rules or guidelines in California regarding rent payments when a rental unit is temporarily uninhabitable due to repairs?

If my post comes across as salesy and violate some community guidelines, I apologize and that's not my intention.