Oh, and to answer the first question:
Saying it's the 'electronic structure' is extremely vague. Everything in chemistry is due to electronic structure.
The basic reason for this property is the way that metals bond. The outer electrons detach and become delocalised, not tied to any individual atom. The metal atoms are held together in the lattice structure by this 'sea of electrons'.
However, as there aren't bonds between specific atoms, the atoms are relatively free to move, which means that you can cut it, bend it, or whatever, with relatively small effects on the rest of the structure.