Although there are many reasons for people who never smoke to develop COPD (I will discuss those at the end), consider that a diagnosis of COPD is based on numbers
that come out of testing equipment. Numbers do no necessarily mean disease, especially if you have none of the symptoms of COPD.
I am not sure how your diagnosis of COPD was made. Sometimes, COPD is diagnosed on a chest X-ray, which is not the best way to make the diagnosis. For example, taller or thinner people may look like they have COPD on a CXR without them actually having the disease.
The best test to make the diagnosis of COPD is called a spirometry, but even this test has its pitfalls. Even if your diagnosis is already based on a spirometry, I would consider repeating the test to confirm the results. A proper spirometry needs to be done on equipment that is calibrated daily, with technicians that have specialized training, and with results that are consistent to each other on repeated testing. Also, the diagnosis of COPD is made with a spirometry testing that is done both before and after inhaling a medication called a bronchodilator. So consider asking to be seen by a pulmonary physician to confirm the diagnosis.
Even assuming that you had a proper spirometry and it still shows what can be called mild COPD, remember that the diagnosis is based on assumptions of what a normal lung function is, and assumptions can be wrong. Just like there are normal taller and shorter people, lung function can also fall within a too low or too high range in otherwise normal people. In fact there are studies showing that the older we get, the more likely we are to be falsely diagnosed with COPD. As it turns out this overdiagnosis of COPD can start in our 50’s.
That said it is possible for never smokers to have COPD depending on many issues including pollution, second hand smoke, exposure to smoke (like wood burning) in confined areas, genetic conditions, congenital conditions, etc. Even assuming you have mild COPD, it does not mean that this will progress at all, and it looks like it does not need any treatment since you are so active.
So before you start worrying about your two questions, I would just make sure you have the diagnosis confirmed.