It's an introductory book to note investing, but leans more towards seconds since that is what the author invests in.

If that's the case, you arent' covered.It's supposed to be to get a building permit to put in an extra kitchen, (i.e. to make more rentable units) the permit would only be authorized if zoning at the time allowed the quad....or the waiver was granted.Does your seller warrant that all modifications were done to code with legal building permits?

The lease addressed this and stipulated no modifications without authorization.  

@Matt Rogers You need to know the pay off, which the owner can get a pay off letter/email from the lender..... or they can execute an Authorization To Release form and  their mtg co. can disclose directly to you.  

Tenant applicant will have to docusign some forms authorizing it.

Should executive authority reside with one party or the other?

That might be something to check with they local authorities though. 

And I learned that the reason most of the houses go back to the bank is because the bank's representative is "authorized to bid up to X amount for the house," basically setting a reserve price.  

Typically site costs and major soft costs (like entitlement fees that are charged by the permitting authority) have little room for negotiation.

Other authors have written here about that moment when you first have the cash in hand.