I did some research on this question myself some time ago, and though I can't exactly remember why, I became convinced that - at least if you truly are only a few times a year casual drinker- the best answer is (to check) "No Alcohol Use" and just move along.
It's not necessarily a deal breaker for a lot of companies, but it sure isn't a good thing. Regarding your medical card, the best advice I can give is to reply to the questions on the long form in the exact way you think a company/doctor would want to hear. 99% of that #### could never be verified so when it asks "How many alcoholic beverages do you consume in a week" the correct answer is "none." Regardless of whether or not you drink.