My personal experience is that buying adequate insurance and having a contract between you and your sister will be cheaper and better protection in the long run.

They don't know how to adequately explain their situation. 

I’m sure that was an experience in itself, and while it surely won’t make up for the sting of $ flowing the wrong way, I’m sure there will be lessons learned here that can’t be learned without doing.A couple observations: $100 in pro forma cash flow is more than adequate  on a 70k house.  

You drive up the prices by buying up a bunch of properties this making the already less than adequate supply even scarcer.

Until you get 10+ units, maybe... just make sure you are adequately insured...

@Ethan Giller is correct, you are position adequately enough and there are those common options.

There has been some deals that came at a time where I already had projects going and it would have been best for me to have simply shared that deal with other buyers.On a few occasions I have let a couple of wholesaler acquaintances help me find an adequate placement for a deal.  

It would be at my discretion to retain the tenant and property management company, but having an existing tenant seems pretty lucrative at this point.I would like to cashflow for a few months while I take the time to build an adequate team and thoroughly estimate the cost of all repairs.

Before you purchase the property you want to make sure you have adequate repair reserves (for the outlined items and other normal maintenance) and have reserves for debt payments if you experience a short period with a decline in property income.

The 70% minus repairs is just a general guideline to ensure that you have adequate profits and an adequate margin of safety.