I don't think your concern is the cost of rehab vs. lost rent vs. gained rent, because it's all pretty negligible - your real concern is what type of demographic do you want to appeal to with this unit? 

Something like this could arguably fall under the fraud (due to negligence) category, providing the IRS with an unlimited statue of limitations.

The amount makes no difference - its pure negligence. 

What I laid out on purpose were violations of code, negligence or both. 

Also,tell the seller you want the property delivered vacant before you pay him a nickel.Cat lady being evicted is his problem,not yours.Find out what the West Virginia laws are and have him give her the 30 or 60 day notice to leave the state requires ASAP to prevent further delays.Remember,you must put "Seller must deliver property vacant at close of escrow" in the contract so you don't inherit his negligence of a freeloading tenant who's apt is probably a disaster area to be completely gutted.

You could also bring up the smoking as an alternative source of any injury.Alternatively, tenant could file a lawsuit, in Virginia, on the idea of negligence.

Landlords can still evict tenants for non-payment or excessive disturbance or {willful/negligent} damage  - the exact list and wording in your instance will be in the BC Residential Tenancies Act.Items 4 and 7 in your list have to do with tax withholdings (capital gains and income) on foreign nationals when capital leaves the country.  

Update to this : I went and looked at the property with my contractor, one of the tenants told me there was mold in the ceiling that has spread to the supporting beams upstairs, I know there was mold in the ceiling but was unaware how much, and almost EVERY pipe in the basement was wrapped in asbestos, it needed 15k work before the Mold and asbestos, so I passed, that landlord is very negligent, tenant told me he's asked the LL to fix the mold for months. 

Based on the pictures, it looks like it was a live branch though, so it wasn't necessarily negligence on my neighbors part. 

Also, he will learn the cost of his negligence and reconsider his behavior in future.