@Brian FooteHiIt's going to be hard to say precisely without knowledge of your market however those rent numbers are pretty good if I'm seeing the $1600+ for what you're getting into the property for.The 'gotchas' that I see that I'd want you to really be comfortable with would be that repair cost number - this would have to be a pretty light rehab where you're maybe doing a facelift, etc. 

The formula(s) would look like:Potential Gross Income (PGI)  = full rents + any other income at 100% occupancyminus Vacancy & Collection Losses (8-10%) is typically usedequals your Effective Gross Income (EGI)Then you subtract your operating expenses (taxes, insurance, management & legal fees, repairs, utilities, lawn service, pest control, etc., and a reserve for capex) to get your Net Operating Income (NOI)From your calculated NOI, you can really start digging deep:Subtract your debt service from your NOI to get your cash flowDivide your NOI by the acquisition cost to get your cap rateTake your NOI, add the reserve for capex back in, then subtract your mortgage interest, to get your taxable incomeDivide your NOI by your debt service to get your debt coverage ratio (tells you how many times will your NOI will cover your debt/mortgage payment).

With respect to the rental - if it is inhabitable, advertise it for rent before you do any repairs or maintenance.

Any advice on repairs (rotorooter?)

I put away $300/mo for repairs, vacancies and tenant turnovers totaling $1717.

How can I find out what percentages I should use for vacancies, repairs, capital expenses, etc. 

The nuisance and abatement officer said he's going to contact the inspections department on a wire hanging from the electrical meter on the side of the house to see if that'll prompt an inspection that will need to be done, which will have to get the owner directly involved. 

(per the challenge)On the other hand, After Repair Value isn't something you can just guess on.

Dry wall isn't a big deal but it can get real expensive if you have to start cutting out joists and studs and repairing them.

I also budget for repairs (usually 10% of rent) in addition to the CAPEX reserves.