Yes, but only in certain situations. Beer can only be acquired at a bar, restaurant, licensed beer store or distributer. Beer can not be sold before 11 am and a retailer will require a special permit to sell on Sundays. Several supermarkets have attached restaurants, where they can sell take-out beer, but it can not be sold in a normal grocery store.
Yes, but Mexico is already a major producer of beer in the world (for example, Corona beer). Also, most stores sell many brands of beer such as Guinness so it would be a lot more expensive to send and pay the appropriate taxes than just going to the closest supermarket and try to find a good brand of beer.
It all depends on what you want. If you want to offer them a service or sell them your beverage. You need to get in contact with the beer distributor in your area and ask them for a meeting. If you are trying to sell them your beverage get in line because everyone is beating down the doors of beer distributors.