I'm not terribly worried about offending sellers, I buy used items at work all day from people who are offended by the prices I want to pay, but my agent seemed to fall apart when I told her what I wanted to offer.

How low of a credit score should I accept?

I may never see a dime but at least it sits on their credit and possibly stops them from damaging someone else in the future or keeps them from qualifying for a car loan, home loan, etc.I hope you've learned the following:1.

Pull out line of credits on them? 

Fantastic to see how well you have been able to do over there, a credit to you. 

As long as each parcel meets minimum zoning requirements (size, set backs, electric/water, etc.) then it's not a terrible way to do it. 

It's not out long enough for a bank or credit union to see return. 

They also report the individual to a credit reporting agency so it sits on their credit and hopefully stops them from scamming the next person.

Make sure they have great credit so you know you can go after them for damages.

My partner and I have an investor that has a line of credit on his house.