Dangerous electrochemistry

[Chazef]

Questions often ask 'give reasons why this reaction is a very dangerous one'. Other than potassium being very reactive with oxygen and water, and hydrogen being very flammable, what kind of things should I be looking for in terms of the 'danger' of a reaction?

[Inhibition]

If any gases are produced under pressure. E.g. In a lithium button cell, when in contact with H2O the Lithium may explode, not because of the difference in E naught values, but because H2 gas is produced (O2 is reduced to H2), and H2 may increase the pressure, OR a spark may ignite the H2.

Other than that, I think that E naught values are not an indication of the "danger" or "reactivity" of a reaction; it just indicates the potential produced when the 2 half cells are connected.

Anyone correct me if I'm wrong...