comment on watches

Question

I just read a posting from Refael regarding a self winding watch that charges a battery. (At the time I am writing this I have not seen your response.) What about self winding watches that are fully mechanical? I wear a self winding watch that is mechanical and I never take it off. I wear it on my left wrist and I put my tefillin right over it. My father and Uncles put their tefillin on over their watches and I was taught to be very very careful about the the first tightening of the Retsua on the upper arm as a very very important issue with tefillin, and not to be concerned about a watch I never take off. My point now on Shabbat. My watch is a diving model and I never take it off. Not in the shower or even at night. I only take it off every other month to advance the date and twice a year to set the time, and then it goes right back on my wrist. If my math is correct, that would make a grand total of 8 times a year. Question 1. Is there an issue with wearing a self winding mechanical watch on Shabbat? 2. Does the fact I so rarely (only 8 times a year) take it off my wrist have an impact on a ruling? Thank you in advance.