There is nothing wrong with moistening the lips and nose with balm or wetting them with water or with a cloth and the like.

There is nothing wrong with rinsing the nose and mouth while fasting, but you should not exaggerate in doing that lest the water reach your throat.

It is permissible for you to use miswak and toothpaste whilst fasting so long as you are careful not to swallow anything. For more, please see the detailed answer.

It is permissible to use nicotine patches to quit smoking gradually. Also nicotine patches do not invalidate your fasting and you can offer prayers with them on.

Regurgitation does not break the fast if the person expels the food that comes up. However, if it is unintentionally swallowed, the fast remains valid, as it was beyond the individual's control. Scholars agree that fasting is only broken if food is deliberately swallowed after reaching the mouth.

Working as a massage therapist during the day in Ramadan does not break the fast for the therapist or for the one who receives the massage.