We went to the house and did a visual inspection as best we could without being able to get into the house. 

you are not listing the numbers in an order that would help you visualize the whole picture. you also have to have the numbers of the potential rent increase to see the opportunity as well.a quick look shows you that there is potential and it passes the 50% rule since the big 3 (piti) is less than 50% of the revenueuse JScott's spreadsheet and put the numbers in.https://www.biggerpockets.com/files/user/JasonScot...

An inspector may tell you what's wrong with a property on visual inspection of critical systems but won't tell you what needs to be improved to make a property marketable.It seems like a catch-22: how do i get the rehab costs before putting in an offer to get a bid on a rehab?

Numbers first, visuals to verify.

What if there is a second mortgage)I'm not sure the legality of it but I would also drive by and do a visual inspection.  

I suggest you capture screenshots of any issues you discover and send them to the  email address for the BP support staff - support at biggerpockets.comAt least that way they can visualize what you found, and that is the first step to getting things fixed.

That way, people who are visually oriented will learn faster.

I also have a licensed electrician that is very good helping me with visuals inspections as well when needed.

Write an offer, contingent on inspection and visual inspection.

Our non-debt costs are as follows:Insurance: $42/monthProperty Taxes: $125/monthProperty Management Fee: $150/monthIncludes renter insurance for tenant, home warranty for appliances, weekly external visual inspection, quarterly internal inspection with tenant, annual maintenance of property's systems (HVAC, flooring, etc.) and some for CAPEXTotal monthly non-debt costs = $317 which is 24% of the gross monthly rent.