Im fairly new to the RE game but I tend toward agreeing with you and what the indicators you have provided bear out.

These are major things like (all estimated include labor + materials):1. roof with heavy granular loss and near end of live (needs replacement) - estimated $9K2. foundation grading needs - estimated $1k3. new HVAC needed - estimated $12k4. wood rot on housing in numerous places + wood trim repair/replacement - estimated $2k5. new water heater needed on 1 side - estimated $3k6. rotted facia and soffet - estimated $3k7. soil grading - estimated $1k8. bad electrical wiring that must be rectified by electrical - estimated $1k9. exterior vent repair - $50010. broken window repairs - $50011. exterior paint - $3kone entire side is not renovated (which is fine - but still alone needs it's only 10-20K worth of work to make marketable like the other side - flooring, paint, appliances, and cabinets)estimated total without renovated duplex side: $36-40Kestimated total WITH renovated duplex side: $56-80Kwhat's making me think twice:lender and agent are close (not unusual)things that the appraiser DID NOT find compared to the home inspector made it a perfect pass for FHA loan.

The universe of people that have paid of rentals are, more likely than not, a bit savvier than the average bear when it comes to investing/financial matters, so telling them they are "investing wrong" seems foolish.

The cap rate is your key initial indicator for "profit" but when you evaluate properties, bear in mind that many times the current expenses are inaccurate for a variety of reasons, the most likely of which is deferred maintenance which will come back to bite you later. 

An identification number for a U.S. person is a taxpayer identification number (TIN) (or evidence of an application for one), and an identification number for a non-U.S. person is one or more of the following: a TIN; a passport number and country of issuance; an alien identification card number; or a number and country of issuance of any other unexpired government-issued document evidencing nationality or residence and bearing a photograph or similar safeguard.

Anyone else isn't going to want to deal with that AND perhaps the biggest thing is helicals are only estimated on a soil condition.

You sound like you know more than the average bear.

If you had a $1million loan you’d be paying $30k/yr in interest, it has no bearing on your $100.

Same goes for number of LLCs and what to fund them with, since bear in mind that CA tends to be more cumbersome and expensive to have LLCs than other states.California is generally more cumbersome than other states when it comes to taxes and filings.

Just bear in mind that most typical lease start dates are at the beginning of the month (the first).