https://www.narpm.org/find/property-managersThese are more professional and educated PM's with higher standards of Ethics

I reckon the best ethical compromise is to buy a quadplex; live in one and rent out the rest!

I do have huge respect for the ethical contractors who work hard and take it through. 

Do you or anyone know of an agent who actually responds, is investor friendly and/or has experience with investors and has good morals and work ethic?

This was proven to me in an ethics poll about returning an envelope full of money.

So my question is, taking the ethical stance out of the equation, and the social ramification argument, what have you all seen as to the impact that this industry has had on the real estate market in the areas that have adopted some legal form of marijuana.

There's no single line in the Code of Ethics for a REALTOR that they are required to pay you their compensation for brokering a sale if they breach one of the articles. 

Depending on the disclosures the buyer made for the sale of your home there might not be anything wrong .Perhaps the contract had an assignable clause or he advertised will be sold after closing.The agent might appear to not  be ethical but is simply selling a home for a higher price that is under contract  The fact that he did not cancel your contract might allow you to keep the emd or demand the buyer to perform  

Ethical HMLs will not lend on bad deals because they don't want to lose their money and they normally don't want your property either.

In this case, the chicken came first.And you're right about how a good full time agent will eat your lunch, but hopefully within the bounds of ethics and good taste.As a full time (and then some) agent, I'll remind sellers that most part timers tend to treat this profession as a hobby, hoping that while they hold down another full time job, that they'll trip over a couple of deals each year.