At this point, I don't want to keep digging in our heels and possibly have her threaten us with legal action or "withhold rent for repairs," etc.

Lets say I can work out a deal with him and he can maintain his current bank mortgage,  What legal papers between me and him would let me be able to deduct the mortgage interest and taxes, when those mortgage docs would still go to my buddy with his name on em?

This is not even a legal option. 

I am considering doing an online course to get my real estate license in Delaware. 

Search online, identify the ones you are interested in yourself, then contact the selling broker for each property.

So from what I've read online it appears in order to count rental income towards DTI for VA loan you need 2 yrs experience.

@Nicholas Bolcon it's common for there to be a difference between the tax assessor's page and the actual legal use as determined by the building department.

My question (I'm new to this and just trying to get creative) is lets say there is a deal here (whatever the numbers say)... is it legal for me to sign a contract to get equitable rights to the property.  

Go online and research pricing in your area.

You will also have cleaning supplies, legal / accounting fees, and if in your area possibly AC maintenance.