You post reads like most of your palpitations are pretty normal and
exercise should help
reduce them if you
exercise without too much exertion/strain.
A healthy diet, regular exercise, and yes stop smoking, and control your BP and lose some weight will all pay benefits on how you feel. Stress, where ever it comes from, has to be dealt with in a way that works, maybe exercise, maybe diversion (golf, reading, friends... whatever works) as stress and trigger heat palpitation.