There is a poster nailed to the door of the loo in my gliding club; IMSAFE. You all know what it means....there are a lot of conditions that should cause you to decline to fly, illness, medication, alcohol, fatigue, emotional upset. Probably the biggest cause of unfitness to fly, considering modern conditions of employment, would be fatigue, certainly a factor in the Colgan disaster. BUT the stupidest reason for being unfit is alcohol, and I am absolutely in favour of a breath test as a matter of simple routine. Low cost, universal, and if you know you have to take one you wouldn't be stupid enough to drink, would you?
A shame about alcoholics, recovering or otherwise, I have four in my immediate family alone, and if tempted I could easily fall into the syndrome. BUT there are a lot of guys out there who would LOVE to have a job flying for the airlines. If you feel sorry for any recovering alcoholics, give them a job on the ground, and let them get their kicks flying alone where nobody else gets hurt.