My interest for setting up the self-direct solo 401k would be to make real estate investments, in case that has any bearing on the above questions. 

I am not familiar with this process.So, this is what I know so far. 1) zoning -> checked out, he will be able to build his home on his land.2) building permit -> in order to get a building permit he’ll need a survey done.3) survey - before we get the survey we will first find out the integrity of the soil by preforming a Soil Test.4) Soil Test -> after completing the soil test a Perc Test would be needed for the septic tank. 5) Perc Test -> required for septic tank note, the piece of land does not have  a sewer line so a septic tank is needed….

My assumptions going in are that the land would need to have some set of desirable cultivation traits (soil quality and access to water for example) and potentially meet local zoning requirements for agriculture.

I believe it was used previously for the swimming pool heater, as it was situated right next to the heater in my backyard.My concern was if they move or cut it to pieces and if the gas spilled, I will have some sort of EPA hazard waste disposal issue - one of my neighbors said the city will force you to dig 3-4 feet either side of the spillage to make sure no additional soil is contaminated.I took a picture of it, measured it, and posted it on CL, said I wanted it removed and disposed of, and the gas inside feel free to take it but it needs to be completely siphoned out before you can take the drum apart.

The soil is always slightly damp under the 1912 house due to the water table being inches below the ground surface.

In Big Bear and Lake Arrowhead, CA they accomplish this by using a local property management company.

But do bear in mind that if they miss their portion of the payment, they can be considered in default and lose their voucher. 

Its sale price will fetch what the market will bear. 

I got my lots at tax sale, and sold 1 of the 3 in a row, I have also run into snags. like my sewer connection was 17 feet down, so I had to get a big contractor in to dig deep with steel plates to prevent soil from falling in, cost an additional $9K I did not plan for.

Just about every apartment I rented had this option.You'll have to look in your area/market to see what the market will bear as far as these deposits and fees.