You want to make sure it's a good deal now and any further appreciation is icing.As far as negotiating is concerned I would listen to your own voice not that of the agent. 

long term cashflow and building equity through rehab and appreciation How did you find this deal and how did you negotiate it?

Don't be afraid to negotiate!

How did you find this deal and how did you negotiate it?

In negotiating, the one who wants it the most, looses. 

For example I have a phone script; a negotiations script; a checklist to prepare for my appointment to view the house; a checklist to estimate rehab costs that I bring with me to my appointments; and comparable analysis sheet to share with the owner.

Might be more worthwhile to negotiate a MUCH lower price on the property instead to account for cost of repairs.2) Assuming somehow issue #1 is resolved and FHA clears the purchase: I am new to the area, and am not sure what the costs will come out to, but my hope is <$5-6k initially as I start my investment mostly replacing windows and painting (I’m told always to expect to pay more).

How so for being a private negotiator? 

Because of this, I've negotiated a very low price relative to the value of the land. 

Currently I'm negotiating with a seller who is a contractor and has rehabbed a single-family property.