Does freezing water do work?
Long story short, it goes as follows:


Yes, the freezing water does perform some work. You put a load on top of a bucketful of water, and as it freezes, it will lift the load all right.
Yes, a capsule would prevent the water from freezing, at least for a while (provided that the capsule is immensely strong). Then some of the beer (water?) will freeze. Then... see the next item.
No, the absolute zero would not finally break the capsule. Rather, it would turn water into some alternative kind of ice which is more dense than water. BTW, you won't have to get precisely to absolute zero to achieve that.
True, normally increasing the pressure of a substance will cause it to crystallize ("freeze"). Water is different in this regard, which is quite rare, but by no means unique.