I'm finding that the more specific your niche is, the better....and telling people I'm a real estate agent and investor has opened many other opportunities!

How do I decide if its better to keep renting it or to take the equity out and diversify into multiple properties with more cash flow?

.- Worst case scenario, $150k purchase, $40k rehab (or more), $170k value, you're losing a lot of money.IMO, I would pass and look for better deals. 

Bigger risk, bigger reward - but only from a Cash flow perspective.Typically as Sebastian said these are D class or C class at best.While you might be getting a better return on cash flow you are not investing, you are buying a business.

Even better!

If Wholesaling is so difficult in So Cal, would someone who lives in So Cal be better off looking at other areas outside of So Cal?

However, I understand that sometimes due to time constraints it's actually better to hire a professional manager.

Take a look at this blog post, you may be able to better understand your seller, anticipate their pain point and provide a solution they haven't considered.

Most will allow a local override of the program, the better ones put a time limit on the override.

Would it be better to create an incorporation for management?