voiced the idea that they could just shut off the flow of medicines like antibiotics to the USA and we'd be in deep trouble. 

Don't get me wrong, stick to your criteria and numbers #1, but if you're putting out safe (you mentioned low), well-analyzed offers, I wouldn't suggest limiting them just because you're artificially trying to lower the number of deals you have to analyze.

My wife and I both work in medicine and we make a good living.

Think of a LLC, or a corporation, as a separate legal entity with the power of an artificial person according to the law (i.e. enter into contracts, bring a lawsuit, etc). 

Using a larger down payment does not increase real cash flow it simply forces artificial cash flow.

That artificially held prices down for the existing homes.

That lease contract on that business artificially appreciates the value of the property because the cash flow increases over time.  

You have to have both a buyer and a seller that are both willing and able to close in order to create a transaction, and price and terms are the market mechanisms for equalizing supply and demand to create transactions across a market of buyers and sellers ... inefficiencies can occur when there are distortions in the market that limit the number of buyers or sellers or otherwise creates an inequality between buyers and sellers that cannot be easily resolved by the usual market mechanisms of price and terms.Inefficiencies can have a dark side, as eluded to in comments above ... if an inefficiency is artificially created so that a more sophisticated operator can rip off a less sophisticated, weaker, and/or desperate person, that may be profitable and even legal, but can also be morally appalling IMO ... this never gets discussed in polite conversation here on BP but think it is important to understand.

I also look up the county records to make sure there's not a senior discount in effect or other discount creating an artificially low tax.

Many investors ignore the value of money to artificially enhance cash flow.