A few trach questions

I have two hospice patients with new trachs, one for esophageal and the other for bronchial ca. Both have Passy Muir speaking valves, one sounds just like he did pre-op and the other sounds as if he is just belching and is extremely difficult to understand. These are my first two trach patients. I can't put the physiology together to understand why their abilities are so different. (The bronchial guy is the better speaker)

The second part of my question involves O2 via n/c. If there is an interruption in the airway as in a trach, how does the n/c get air to the lungs?

The third part is just a personal aside. The one with the better speaking ability is a smoker who inserts the lighted end of a cigarette into the stoma while the n/c is in place. During my 90 minute visit (the first post-trach) he smoked two full packs despite my teaching (which he has heard and which has been well documented a million times) and my pleas that he not smoke due to my personal disdain for smoking.

As is obvious, he isn't going to quit for himself or for me. (Family issues are yet another aside you can of course figure out). Would you suppose I can professionally, morally, and personally refuse to see this patient? While there have always been a plethora of warnings about O2 and smoking as it aids combustion, do you professionals have the same position on the danger inherent in mixing lighted cigarettes and O2 as we have always been educated?

Thank you for the information.