Typically landlords would describe emergency repair requests along the line of involving "fire, flood or blood" (if this helps).One would assume that a tenant with a lousy credit score, two pitbulls and a yearly income that places her on poverty status would be grateful any landlord would rent to her. 

I  am not recommending cheap materials and cheap workmanship - after all, when flipping, we are not just renovating a house, we are creating someone's home.I agree with Aniekan Udoh, stay in line with the comps.  

Broker, direct mail etc.Direct marketing / cold calling is always a good bet, in the commercial world if you get a hold of a building owner in a principle-to-principle setting you can generally have some good conversations and suss out if there is an opportunity or not. 

Build it on excel is the best bet... you can adjust it for use in the future

The reason I said that is because I already have some partners and a hard money lender line up that is willing to do some projects with me (on flips) once I can show them a great deal.  

For $6K, you should be able to replace all the supply lines in the house, plus some of the drain lines. 

So you probably need an attorney to help you with this versus a property manager or any lease forms you can find on line. 

The MORE UNITS you own, the less losing a tenant will IMPACT your monthly gross income = BOTTOM LINE.

Your best bet would be to do a tear off of the existing roof, inspect the wood planking for rot then re shingle it.

I would highly recommend using one of the Providers on here (I use @Dmitriy Fomichenko and have been very happy with his services) , they are not directly allowed to promote themselves on here, but just look at the signature lines and you can tell who they are.