I am the custodian of the Solo 401k with checkbook control.

Some cities control how much you can raise the rent.

Essentially, the seller of the note maintains control of the security in case of default.

Cash flowing properties (rental property) is delayed gratification, however, it is your path to wealth if you know how to control the cash flow and reduce risk of bad tenants.

I can see good opportunity in Oakland (looking specifically at opps in West Oakland and Maxwell Park) but am worried about rent control.

However I must admit I also always invest in other sources of incomes so I invest in private companies where there is offered some control to me the investor and I do not ever depend on any management team that does not offer me decision making power such as in publicly traded companies.

The City (not the county) controls the zoning.   

Neither you nor I can control that.

Counting on assumed future events that you have no control over isn't investing...it's speculating, which is another way of saying guessing. 

What might need to learn how to raise money and form Partnerships where you stay in control.