Enzymes and alcohol are practically a non-issue in my book.
A thing of potential concern to CFers is that alcohol is a depressant and causes dehydration. When our bodies are slowed down because of the depressant/sedative effect of alcohol we aren't able to breathe as deeply. This is problematic in conjunction with the dehydration. Our mucus is already so thick and devoid of the moisture needed for it to be slippery enough to come out when we cough. By creating a drier environment in our bodies and one in which we're not coughing as effectively, the alcohol has the potential to create unwanted problems for CFers.
If you have CFRD, alcohol presents a whole other set of issues with blood sugars.
Personally, I drink infrequently for a variety of reasons, but most of them are centered around my overall health.