Don't listen to the noise.

Without knowing what your goals are it's very easy to get lost in the noise of everything that revolves around real estate.  

Their complaints include noise from the floor above, stating they want the floors to be torn up and redone with superior soundproofing.

Residential tenants aren't going to want the noise and traffic from the warehouse user and the industrial tenant isn't going to want the hassle of complaining residents next door.Any chance that could be remedied by converting the warehouse to more residential units?

Seems like you'd want to have a really good inspection and really understand what kind of noise/home life you'd be subjecting yourself to.  

They would be using each side of the unit less-- less wear/tear, less potential neighbor conflicts among duplex tenents, less noise to surrounding properties, fewer cars to park.

Problem is that the wheels of justice grind slowly and you cant sell the house until he releases the loan.

Doesn't that imply partying, damages, high noise levels, and lots of turnaround?

Only one citation for noise over the years.

The cam also gives scary neighborhood alerts; Man checking cars | Car surveilling neighborhood slowly | Lost dog wandering | Heard a loud noise | etc.