@Michael MedeirosThe recommendation that you speak with your CPA is a good one.Sometimes it makes sense to go through a bunch of hoops to qualify your by nature passive investment earnings into earned income so as to sponsor a Solo 401k.  

There are other differences of course  reporting, resale times State Approvals, SEC pre approvals, Suitability Standards, and advertising methods.  

The friend wanted to introduce us for several months but it just naturally happened.

I use small contractors who like my method because they can work around my schedule and they know they are in an out quickly with no obstructions in their way. 

This is the true real estate entrepreneur, going the extra mile(s) to put deals together.

That´s what´s on my mind right now, but I am actually very open to learn about different investment methods here in San Francisco and which will fit me best. 

I see a lot about how you should secure your method of financing prior to looking for a property.

Any suggestion on the easiest, safest, most legal and feasible, aka "the best," or "ideal" method of completing the actual sell of the lease option in California, for 2016? 

My method to date has been buying a house about every 1.5 years.

Paying cash for the 1st rental is key and it is great you have the equity from your primary to do this.So I spoke with one lender that deals with investment financing and this is the method.  1: buy house with cash2: remodel and improve with intention of buying into equity3: (this is the tricky part with time)  Wait 6 months (some make u wait 12mo)  and get reappraised with intention of financing for 70% the appraised equity.4: Use the 70% pulled from 1st home to buy your 2nd property.This method works better in flips because once the 1st home is sold you can do the method over agian.