They’re “meaner” than me so they charge late fees (I get 1/2), file pay or quits, and increase rents faster and further than I would.

So, I would work to increase your knowledge and experience and really identify a strategy that suits you before moving forward with anything. 2.

We have an existing mortgage (backed by these 2 lots and 2 others) and given the increase in appraised value there is no need to pay anything back to the lender when selling the lot.

But, the self-sufficiency test for FHA loans can be really difficult in SF, meaning that the market rent from units you will not occupy must be sufficient to pay for the mortgage payment. 

Like Rich said, starting reading and self-educating. 

Upon BP member recommendations, my husband got his real estate license which now helps increase our access and decrease our transaction costs.

I used a RE agent to show vette and place tenant for the first months rent.. then I self managed..

Finding deals outside of California can definitely open up new opportunities, especially given the cost of living and market dynamics in the state.When looking for properties in other states, consider focusing on areas with strong rental demand, economic growth, and population increase.

If you plan on eventually selling, central air would add a significant value increase, so you may consider if that's the case. 

Part of that is adding additional cost for increase in building products.