Question

3) Why did the Revolt of 1857 spread throughout India?

Answer 1

The Revolt of 1857, is quite overrated. There were several revolts by the erstwhile nobles or peasants or the tribal groups as well as military mutinies during the same period (Vellore Mutiny, Santhal rebellion, The Wahabbi uprising by Titumir ,Sannyasi Rebellion) and none of them are given as much attention as this one, simply because V.D Savarkar decided to name it the 'First  Indian War of Independence'. It could not have gone beyond Northen India anyway.