I believe that most people on BiggerPockets are ethical and wouldn't take advantage of me posting this but well this is the internet so caution is a good thing.Looking for advice on weather to try to stretch myself right out of the gate or to let it pass.

He has been to treatment he says he did more drugs in treatment than on the outside.

If the deal is meant to be bc you stuck to your guns with your purchase, rehab, holding costs and an ARV selling price then you will be successful.With that being said I have few answers to some of your questions above:1) I am not a realtor however I do believe realtors have to follow a ethical code when representing facts about a property? 

Frankly, If you sign a contract to buy a house at an agreed upon price, I think, ethically, you should perform or walk away without tying up the seller any longer.

I believe in ethical business dealings and honesty in relationships.  

As I said, there are always bad apples with bad intentions, but for those who are wanting to deal ethically and legally then information is available and there are reliable sources from which to gain knowledge.......but it sure won't be from some guru!

You don't have to have any ethics!

That fiduciary responsibility to the buyer will be one of mere ethical concern but he/she will be representing your best interest and has to make seller aware of that.

I have extensive sales and negotiating skills, a big sphere of influence and a very strong work ethic.

Ethics are not legislated in many cases but imposed under our legal system under concepts of common and uniform law.