Investors would only be afforded a return on their money from the interest on the loan and we would make our cut on a little additional interest and the points on the loan.

Make sure it comes across as an honest mistake and not them purposely misleading you....otherwise they will immediately get on the defensive and you'll have a much harder time negotiating a price cut.

But if things don't go as planned, I'd look to sell to cut losses.  

Cut those things off that are not going to help you reach your goal.

I can refi without a tenant in place (or could in the past...cut back at the dayjob, so not working too much anymore), but she has to have a signed lease showing there is a tenant so that the rental income offsets the new debt when she refis.

Do they need to cut drywall to do all wiring or will that be done by others or already open to the studs?

There is the relationship component to it, and it might be short sighted to cut him out, even if you can, if there is longer term opportunity to stay on his good side.

My safety man at work is also interested in the method so we are going in this together.

Very likely, the snake that has a claw in the front cut through the filter and went into the septic tank.

I'd just leave it be unless you feel it's a safety hazard for fires having a garage full of flamable junk or an invitation for mice to breed and habitat in countless boxes of old smelly clothes that they'll never wear again.