Previous owner / bank could have sprayed a toxic bug spray which could be an irritant if not done properly.

Spray Foam in basement and attic.

The fix for that is usually shutting off the power at the box on the side of the house where the cable from the A/C connects, hosing it out with a garden hose (use a wide spray nozzle rather than a thin "laser beam" of water, so you don't bend up the fins on the condenser), letting it dry out for a couple of hours, and then turning the power back on. 

For the drafts, you can do spray foam around the windows and doors, replace weather stripping, etc easily enough. 

As water began to spray out of the cut I began to close every valve in sight, but water continued to spray out.

Went in before trim was on and sprayed everything.

slumlord is a pretty harsh term, however, let's say-Its a rough neighborhood (some spray paint and busted windows on various bldgs)-A bunch of 2-4plexes on the block-the living conditions of current tenants is bad (partial electricity, no hot water, holes in windows and walls, rats)-some visible mold on a couple walls-doesn't seem to have had any management/maintenance at allOwner hasn't been able to sell for a few years.   

Long story short.....I've called and cancelled my lawn fertilizer company becasue I was unhappy with the results I was getting after a year and a half of using them.  2 weeks later I see their sign in my yard as if they had sprayed my yard....and left a bill on my doorstep. 

for around ten bucks you can get pepper spray ,a pocket, mace .etc. that way if you won’t carry a gun then atleast you’d have a chance .

I’m a big fan of spray foam, it costs a little more but long term your heat savings pay for it.