Emerson Zollos,I'm in the same boat with a duplex, where one of the units was occupied seems to be a chain smoker - the walls, ceiling & floor are just completely saturated with cigarette tar/smoke.While I haven't begun rehabbing the 2nd unit, I've been doing my homework on the best way to tackle this project and what seems to be the most effective treatment that I've found so far, short of ripping out the drywall/plaster & lathe, I've been reading that using a TSP solution with warm water very effective in removing the "gunk" so to speak - once the walls have been thoroughly cleaned with TSP, use an oil-based primer (Killz) to seal the walls and then apply a few coats of paint. 

And when negotiating for a price with the seller, you need to be able to start lower than that.There may be other creative solutions, but I haven't gotten that far myself yet.

You really need to dig in to get a firm grasp on your final solution.

I know a Business LOC provider for example, and their minimum credit score requirement is 720, and they prefer someone who makes more than $50K/yr.Make MORE money first while simultaneously increasing your credit score and LEARNING how to find deals in the market you want to buy.That's the solution to your problem...not borrowing more money.And read my story - that's exactly what I did starting with $0.

Were you able to figure out a solution?

one of my businesses is basement repair/waterproofing...it sounds like the cheapest solution (which will also work as opposed to cheap that costs more later) is an interior weeping system to relieve the hydrostatic pressure which created the problem and then a vertical I beam buttressing system.

The same is true the other way around - you cannot unmotivate a motivated seller.My time is best spent working with motivated sellers and finding mutually beneficial solutions to their problems.Anything else is a waste of time for all parties involved.

Check out this article for some questions that should be addressed on that agreement.Realistically they are on the note with you, so I would place the responsibility on them (as much as possible) to help find a solution.

Just look at value add solution. 

I guess a fence could be the best solution, but I wonder would others just evict the tenants animals?