(a) if you reach a verbal agreement, you want this in written form of a contract with all of the appropriate addenda, if required.

Any other way requires more risk than may be appropriate to take on?

Any advice is appropriated.

After the appropriate time of seasoning I can refinance the property into traditional financing and cash out the private loan I got on the property.

A human will give you the opportunity to argue for $1500/mo, perhaps after reviewing to confirm that you indeed have your own lease that only obligates you to $1500/mo, or otherwise grant an exception if appropriate.

There are just so many different scenarios that play out on a cold call, that you can't possibly train them to react appropriately to all of them. 

By not going into situations that call you out.Be conservative in ALL OF your rehabilitation and other estimates, ESPECIALLY your estimates for rehabilitation.

It’s been rehabilitated a lot and more improvements to it.

Obviously do appropriate analysis, but if you take too long to jump on something, it'll be too late.  

I’m meeting with seller and I want make a offer that’s appropriate and I’m kind of unsure about repair cost.