Recurrent lung infections, purulent sputum, clubbing made you suspect bronchiectasis. Your suspicion is justified but you have made the diagnosis of bronchiectasis without asking for the lung findings. Shouldn't you consider other possible causes like lung abscess.
His stools are bulky and float in the toilet. So you suspect fat malabsorption. This is justified. But then you straightaway attribute it to pancreatic involvement. How are you so sure? Why can't it be a malabsorption syndrome due to intestinal lipase deficiency.
You link the azoospermia with bronchiectasis and chronic pancreatitis and come up with the diagnosis of cystic fibrosis. This is justitified but my point is: you have not established bronchiectasis or chronic pancreatitis yet.
You asked whether the sweat test was done. Yes it was done and the chloride value was more than 60mmol/L. Now, this sweat test confirms the diagnosis of cystic fibrosis and your diagnosis (like the diagnosis of a few others) is correct. But I would have preferred it if you had asked for the lung findings on auscultation (coarse creps bilaterally), asked for the organism identified as the cause of his lung infection (Pseudomonas aeruginosa is a rare cause of lung infections except in cystic fibrosis) and asked for his blood sugar value (elevated because chronic pancreatitis causes diabetes) before you made the diagnosis.