I was driving around looking for distressed properties and saw one with a sign on the door saying it was vacant.

Many agents will balk at this but in CO it is very easy to do...just takes buyer and seller to sign a form that they acknowledge 1 agent is representing both sides.

Bill never gave Kevin an Agency Disclosure form nor spoke to Kevin about Dual Agency and any kind of Agency disclosure was never signed.A Contract of Sale was faxed to Kevin from the Seller, let's call him Mike.In June 2017, Kevin reviewed and signed a Contract of Sale as the Purchaser for a Property in Brooklyn, NY and put down close to $400k for the Deposit on Contract (Earnest Money).

I assume the reason you selected this route would be learning and trying to do a lot of the work yourself. 

Do they put up a For Rent sign in their yard on their own?

I would also like to include that we signed up for 1 year lease agreement and it ended in October 2017, we stayed in the house until February but didn't signed a new contract so basically it was a month to month lease situation.

You can use a different investor friendly realtor if yours is not making the grade, just verify if you signed an agreement with them.Good luck.

Long story short, I had a tenant lined up, and we were going to do the lease signing this Saturday, and he calls me Wednesday to notify me he was let go from his employer.

We have everything but one signed document back from the seller.

Since you are not adding another unit or doing New construction, you should not have any problems going thru the building plan approval or getting your finals signed off as long as you meet their guidelines.