I have done flambe in an apartment for that very dish, but I agree that a date probably isn't the best choice for trying it for the first time.
You CAN produce a serious fireball with enough booze, although it doesn't tend to smoke very much, if at all.
In regards to fire suppression systems, smoke sets off smoke alarms and heat sets off sprinklers. Smoke, in ANY amount, will NOT set off a sprinkler system. Still, you might want to try this at another time, as I agree that a building-wide fire alarm will not lend to the romantic atmosphere.
You could, I suppose, add the brandy and flame it like a few tablespoons at a time, minimizing flare-up with each addition, but I'm not sure what effect the multiple flare-ups would have on flavor, if any.
I agree with the "add brandy without igniting and let alcohol evaporate" sentiment. Coq Au Vin has enough cooktime, in various stages, with the pot lid off that all the alcohol should evaporate with no issue.
I LIK3Z PORK