That was a bait & switch as no one ever met the requirements for zero down, so everyone had to put down $3-5k on $80k houses. 

Did you do this deal or was it one of your clients? 

Surround yourself with successful agents, not ones that are selling 1-2 a year and struggling. 

When you say 'legal one family', do you mean that it is zoned for single family residential?

One time upon departing a tenant left 22 missing or burned out light bulbs in a 3 br house. 

Call 3-4 of them with 4.5-star rating or better, ask what their experience is and how they can help your situation, then choose one and move forward.You are in the most heavily regulated state in the country, and one of the most regulated/litigious places in the world.

One in particular has organizations referring him tenants left and right but can't buy enough properties fast enough.

I also have been trying to create a due diligence check list, a thorough one.

Once you see the best ones you can check on local rules and zoning, etc

I know one builder was better than the other.