I told her I was keeping a part of the security deposit for cleaning and this is when things changed.You see, she brought a friend with her that was truly unnecessary.

That's absolutely unnecessary.

In both cases, the component that adds unnecessary risk is the "hope".

More specifically in a case where the debt is in ones personal name which is the standard advice on biggerpockets.Whether a property is held in an LLC or ones personal name it's probably assumed that there is "a ton of insurance coverage" to go after.Acquiring credit in the name of an LLC without a personal guarantee is very difficult so good luck getting a loan if your personal credit is already trashed.As for your insinuations on my ability to run a business they are unnecessary as well as unfounded as I've owned an unrelated business for 8 years which has been my sole source of income and is the reason I am able to invest in real estate.

Biggest mistake landlords make that introduces unnecessary risk is accepting the wrong tenants.

Some +/- arguments:+ diversification over cash flowing and appreciating assets+ building sweat equity in my next primary in San Diego+ tax advantages on a larger primary+ taking advantage of the cool market, that’s selling low and buying low (please comment on this)+ having fewer properties to manage (yeah managing duplexes is not my favorite)- high interest rates - high price to rent ratio in San Diego - giving up cash flowing assets - unnecessary transactions costsOther arguments are welcome.

If this is a long term rental this just seems to be adding unnecessary complication. 

I think it can add an unnecessary financial risk, to both be dependent on the real estate business for income. 

If it is a high-end home it may make your home better than home X, but if it is a middle to low end home it may be unnecessary because your home isn't competing against homes with brand new kitchens, golden toilets, and a landscaped lawn.In summary, I would lean toward focusing on what my competition's homes don't have, whatever it may be (landscaping, new kitchen appliances, 2 tone exterior paint job, etc.) before putting in a sauna. 

Not to mention picking up the rent routinely w cash, theres a little danger involve with that and its unnecessary with all the options available..