Yes. One can of regular beer = 1 shot of hard liquor.
Yes. For some reason, a lot of folks think they cannot have an alcohol problem because they only drink beer. I've had patients who drink two or three cases per day. If you know you have a problem, but continue to drink, you should definitely seek help, preferably with an addictiologist. One or two beers per day is usually not a problem. A six pack or more per day usually is.
Yes... But to be clear, like many other liquids, beer contains alcohol in varying concentrations. This site will tell you how much alcohol is in your favorite beer: http://www.Alcoholcontents.Com/beer/.