In regards to the damper situation, do not install a baro unless the manufacturer recommends one. I have been told that my Hitzer runs best with a MPD. My previous stove, Harman, recommended a baro.
It appears that the reason a manual damper is ideal for my Hitzer 30-95, is because I have a bi-metallic t-stat air control on mine. So if the draft changes for any number of reasons, that will open or close accordingly.
If you do not have that, and you only have knobs to control air flow, no t-stat, then I would bet that a baro is recommeneded. In the end, just follow the directions.