It's never been an issue for me. I bring home beer from England each Christmas and I've brought wine back from Italy/France.
I always bring back 2 cases of piton, from St. Lucia. Never had one burst, but it is possible for it to burst, so wrap it in cardboard carrying case, or plastic bag. Not fun picking glass out of your clothes. Never had much against smelling like beer though.
Seriously, it shouldn't burst, and its unlikely, but it does happen. Never lost any Jack when the bottle was sealed. After you open it, it is more likely to leak, but never had any problems with unopened anything. Bottom line, wrap it good J.I.C, but don't worry about it after that.
And as far as the legality. I believe that there can be some restrictions on how much you can bring. It used to be enforced a lot more stictly when alcohol laws were more different from state to state. But, I think technically it is still illegal to transport more than 2 cases across state lines. I know Minnesota and Iowa laws on what you can call beer differ and could still be a sticking point if you transport more than 2 cases, but what you would have to do to draw attention to yourself is probably much more worrysome.
I dunno about beer, but liquor is restricted (I think beer falls below the %alcohol content that liquor falls under)
Something along the lines of 30-70% liquor is allowed in checked luggage, up to 5 liters of it (so no Bacardi 151 or Everclear, in any quantity)
Stuff containing less than 20-30% isn't restricted I don't think...
You can find all that info on TSA's website (aka the people that set the rules for Airlines), though they recommend checking with your airlines for any futher restrictions.
Google "How much alcohol can I take on a plane?" Should bring it up as one of the top links (yes, I'm being to lazy to link it myself)
I have always carried on wine or beer. I don't think pressure is an issue, but temp might be. Some cargo holds are not heated and your beer will free and explode.
I'd guess that most of the time you get a broken bottle it is due to rough handling rather than pressurization. Just make sure to use lots of padding. We brought back 9 bottles of wine and 2 bottles of champagne back from France. Just wrapped it up in our clothes and had no problems. We claimed it all (you are supposed to pay a small tax on bottles more than 1 per person), but they didn't even charge us.