I wouldn't worry about the cooking or about any spray that doesn't actually fall into the tank after sprayed into the air. Also, on the cooking - - unless we're talking heavy fumes from something done wrong (can she cook????
), I guess I don't see a problem.
As far a smoking goes, I'd consider either using an air cleaner (plug in type, sits on the floor w/filters etc) or the obvious...you know. I'm not sure one smoker out of the house for 8-10 hrs daily and sleep for another 6-8 hours can smoke enuf in there to be a problem. Not sure, but that's my uneducated input.