In both of those condos, they had already reached their rental quota, so no more rentals, and they had a waiting list for in the unlikely event that somebody gave up their rental slot.And some condos prohibit or limit pets. 

For instance, did the exclusivity period prohibit you from purchasing a property in any manner, either by yourself or through another agent that listed property your agent did not list? 

Please note that in general the Dodd-Frank law prohibits a builder/contractor from seller financing a residential property to an owner occupied buyer. 

What you described cannot be done with retirement funds because of the prohibited transaction rules and a distribution comes at a major price (taxes and penalties).

If an investor finds a short sale candidate and can convince the homeowner to attempt a short sale, there is nothing unethical about the homeowner contracting with the investor instead of some other buyer.The unethical part comes in when it's not an arms length transaction or when the buyer rents the house back to the seller -- these things are prohibited by the short sale agreement with the lender, so doing these things constitutes fraud.Also, in a situation where the seller would otherwise be in a better position by going with a different buyer (for example, if there is going to be a deficiency against the seller), then it's the agent's responsibility to protect their client and look for a better/higher offer.

I live in San Diego but the real estate market is extremely prohibitive and too many people rely on appreciation as cash flow from rentals is so tight.

The personal loan may provide you the up front capital, but be prohibitive from a debt standpoint.

I have seen multiple people discard properties on account of the drywall alone, and do not understand why, when the installation of paneling does not seem to be prohibitively expensive. 

But the Ohio Revised Code does not (by my reading) actually prohibit a landlord from accepting a partial payment and then doing an eviction the same month though I have heard several people say that the law is commonly applied in that manner.

High rent doesn't mean anything if the price to acquire the property is cost prohibitive.