Follow local laws to ensure you are not exposing yourself to liability.2.

Are they doing everything they can to expose properties to the widest possible market?

Additionally, you are not exposed to any one particular geographical area going bad. 

@Harold Groetsema while you do not have to have an LLC to flip properties in your retirement account, depending on other factors such as total balance of your 401k, the types of investment activities you conduct, the amount of risk you are exposed to - LLC might be helpful tool to limit your liability for that particular investment.Since flipping activity is considered to be active business the gains will be subject to Unrelated Business Income Tax.

In the meantime, we received a letter from her attorney demanding one month's rent, early termination with no penalty, and her entire security deposit.The mold specialist wrote us a letter stating there was no mold found in the home, and we discovered the tenant's pets had used every exposed piece of carpet as a litter box.

The best way to expose yourself to all of the options out there is podcasts, but here are some common ones:Single family - flipping, rentals, short-term rentals (AirB&B)Industrial and triple net leasesMultifamily - apartment syndication for larger properties Storage units Also, if you're interested in being an active investor (doing your own deals as an operator), or being a passive investor is really important to understand! 

I'm buying a duplex now and I obviously don't want to be exposed to the legal risk of being a landlord, yet I don't want to overpay for insurance if I don't have to.

@Rick HarmonYou encourage and scare me in the same post :-)So you have done plenty of RM deals, but at the same time there is a HIGH possibility of exposing yourself to kids protecting their meal ticket and claiming elder abuse.

Are they doing everything they can to expose properties to the widest possible market?

The only time I see "selling to buy" as a viable strategy is if there is some degree of certainty that my sell property is going to suffer some type of economic set back, and my buy properties are going to return at least as much cash flow to me (including the recovery of sale costs and loss of cash flow from that asset) , appreciate at the same rate or above as the asset I sold and the by assets are NOT going to be exposed to the same degree of potential economic set back as the sell property.