While i haven't looked into it directly, i would caution by reading to much into english conjunctions.
I think Kai is used here.
So KAI can be translated "and, also, but". it is however more of a placeholder for the beginning of a sentance.
What is more interesting is the final word. Some apologists (including myself back in the day), used to suggest the "good health to you" was almost like a prescription for lack of a better word, from Luke the physician. Now that seems luicrous, but there was a point made by a prominent JW apologist on the matter in the late 90's early 2000's.
What is translated as "good health to you" however, is a bit of a stretch. I copied below from studylight.org.
Not trying to throw salt on your point, I'm just not sure the "if" hold the same weight in the original language which could hurt your point.