I have no problem creating a single-member LLC, but I have read numerous time that refinancing out of the loan could be problematic.

Numerous amazing BBQ's and cool downtown feel.

El Cerrito (quick access to 8 and 805 freeways, just West of SDSU, diverse neighborhoods, commercial district with numerous amenities)2.

Without having any specific knowledge as to this particular property, there exist numerous reasons a seller may sell multiple properties together, such as the properties may be mortgaged together or cross collateralized, there may be an accessibility factors to one or both properties that requires access to the other, they may share common parking, they may be on one legal lot, they may share a common building and hence be less attractive trying to legally separate, one property may be unattractive to a buyer by itself or at least more difficult to sell on its own, they may share utilities on one infrastructure (line), the seller may be receiving a discount on broker fees if they sell together, the seller may have adverse tax consequences if only one of the properties sells, the seller may be trying to do a 1031 exchange, there may be multiple owners who won’t be able to reach agreement if only one of the properties sells, and selling only one of the properties may not accomplish the sellers goals; in fact selling only one of the properties may take the seller further from his goals than not selling either.  

There are numerous RE investors in San Diego who added an Adu only to be disappointed by its valuation.  

While it covers different aspects of real estate investing, there are numerous episodes dedicated to multi-unit investments and flipping strategies.4) "The Apartment Building Investing Podcast with Michael Blank"- Michael Blank focuses specifically on apartment building investing, and his podcast offers valuable insights and strategies for buying, managing, and flipping multi-unit properties.

The 'diamonds' that are listed for $30-60k that were numerous back 2-5 years ago (over supply of foreclosures, etc) are really not there anymore. 

I read house flipping for dummies and other real estate books, gone to numerous 3 day real estate seminars, purchased $300 real estate cd programs, joined real estate clubs, and talked to other investors.  

Your economies of scale will be better if you have numerous properties in one market instead of a couple in a few markets. 

This is subject to numerous rules however, so I would suggest you work with a CPA who is well-versed and experienced in that area.