I am not going to try to restore the hardwood floors so I dont care if they get ruined if I apply a odor removing chemical. 

I will allow them to cure the cat problem by also obtaining professional carpet cleaning which specializes in cleaning carpets with cat urine and soil, and perhaps a warranty against cat odors.

If they are being considerate and giving adequate time for the old landlord to find a new tenant no harm no foul.

But, I've found that a litigious agent could come back and foul up any transaction.

No foul.

My concern was that I have known people who only smoked outside but their clothes, car, and in turn the house eventually had somewhat of an odor to it.

We look at many properties in Houston and termites are never brought up by our clients unless there is obvious foul play caught by our inspections.  

It really knocked out the odors.

Biggest expenses will be roof repair, flooring, exterior and interior paint, some replacement windows, and cleaning/sealing the interior due to nicotine stains/odor.

My question is can I charge the tenant and security deposit even if the unit is in such terrible condition or should I give him a 30 notice to clean and get rid of that odor before I do my walk through?