I do not think they are sketchy is just that they do not go by all of the state regulations and they might charge you a cancellation fee or increase rates more often.

Ideally, I’m looking for areas with a mix of:High occupancy rates for STRs (Airbnb or VRBO),Solid potential for appreciation over the long term,Investor-friendly regulations on short-term rentals.If anyone has experience with markets that fit these criteria or knows areas where STR is thriving with good investor laws, I’d love to hear your thoughts.

By-right uses are much simpler since they don’t require additional government approval beyond standard permits.Development Standards: Once zoning is clear, factor in the regulations such as setbacks, parking requirements, density, and other local standards.

 @Eric CarlstromRegarding taxes, be sure you are not paying too much and that your CPA/tax professional is up-to-date on the regulations.

Question 2: Where can I find state or city regulations regarding tree maintenance when the lease is written with gray areas?

The regulations in Chicago can be quite overwhelming, so I’m looking forward to exploring the opportunities in this area. 

Be aware of any local regulations in Emeryville as well.Please make sure your 4plex isn't exempt from AB 1482.

When I appraised notes for the State of Missouri, the very first question I had was "Is this obligation enforceable, was it in compliance with rules, regulations and laws at the time it was originated?

Use some for buy and hold (I personally would prefer apartments rather than buying a few single family homes) and some for lending/trust deed investing.In either category, you must know what you are doing, know how to vet the investment, how to vet the sponsor (if investing in a larger fund of some sort), the laws and regulations on the lending side, how to investigate which areas to invest in buy and hold and notes/trust deeds for that matter.So as you have already said several times, lots to think about . . . 

Your definition is correct for "legal non-conforming".The "legal" part of "non-conforming" is dropped when it doesn't apply so most commonly people call these units "non-conforming", "finished", "in-law suite/unit", or "bonus unit".Non-conforming: Any property that doesn't meet current zoning requirements.Legal non-conforming: A non-conforming property that was lawfully established under previous zoning regulations and is allowed to continue its use.Based on his posts @Mario Morales is referring to a non-conforming unit.