Multiplication is better than addition.

What additional data would you gather remotely? 

Depends on your learning style.

PM me if you would like additional information.

In addition to a legal egress window, a bedroom must also have a closet.

You can also structure in some additional terms about who and how significant repairs are handled, but that will also tend to tip in the owner/investors favor.* When selling a property on a lease option, realtor commissions are not necessary.* Check your state laws and talk to a REI attorney and escrow/title company about facilitating the transaction and all the needed paperwork for your area.

My combination of forced appreciation Multifamily Millions style (David Lindahl), has allowed me to not only experience over 3 times the cash flow I was getting on those condos in San Diego, plus exponential appreciation.  

( addition tore off, or are you exaggerating the roof)  based on your project details, id guess 45k+ in rehab .... building a second story would be out of the picture for me.  

At which point I would have to come out of pocket ($18k additional for $80k total renovation) to succeed in renovating the property to its full appraisal potential. 

Will you need to put additional time and money into this to make it a viable rental?