The purchase was effective when the deed was signed and delivered to you.  

I want to learn how to flip houses, I know learning everything myself is not very effective, I need a mentor.

This has the practical effect of me having investor clients out there that I've done mortgages for already that are "permanently preapproved" for however much cash they have on hand for down payment plus closing costs because while I do not know what their DTI will be, I do know that it will go *down,* meaning that I do not care about it.Note that the lesser of current lease agreements or appraised market rent will be used, unless you can demonstrate that the current tenant will be departing the residence.

Effectively completed the commercial real estate due diligence and document handling of a 26 property sale. 

So enter, stage left, the "new guideline" that just came into effect 7 days ago, that no one can show you a copy of dated 7 days ago, and THAT'S the reason your loan is jammed up.

Though it all comes down to the fact if you have a blanket inspection contingency in effect you can back out for any reason at all!

It's proven effective over time.

It may take some really embarrassing media story to really effect positive change.  

Now knowing that this property is under a leasehold agreement how does this effect the value of the property?

It like most other things in investing you must learn all about to use it effectively.