Alcohol is TERRIBLE for ANY pet. It's not exactly poisonous or anything but you have to keep in mind that your pet is much smaller than a human and can get drunk VERY quickly. The sugar in the alcohol can also mess with your dogs blood sugar levels and cause some serious problems.
Yes. It really comes down to their weight. Would you give a 4 year old a beer? This is about the same thing as giving a beer to say a 40 pound dog. The alcohol content will affect them at least 4 times more that it would for yourself.
Yes! Alcohol, hops and carbonation are all bad for dogs. Dogs are susceptible to alcohol poisioning as well. But there are doggie alternatives available on the web: non-alcoholic beers made specifically and for dogs.