What are the different causes of the animals' rebellion in Animal Farm by George Orwell?

To a great extent, the animals who rebel do so out of
opposition to Napoleon's actions as leader.  There are some areas where there are
differences as to why they decide to rebel or openly question his actions, but most of
it boils down to dislike of Napoleon as leader.  For example, three hens consider it
murder that Napoleon demands that they surrender their eggs in order to fulfill the
arrangements he has made with Whymper.  In destroying their eggs, this represents an act
of rebellion.  When Napoleon wants to end Sunday meetings, some porkers disagree.  In
their dissent, another act of "rebellion" is construed.  When Boxer questions Snowball's
retelling of history in suggesting that Snowball was actually treasonous to the ends of
Animal Farm, it is seen as an act of rebellion.  This becomes broadened to any animal
that engages in a collaboration of any kind with Snowball.  The cause of these
associations are the belief that Snowball could be a better leader and possesses better
ideas than Napoleon.  In the end, the dissatisfaction with Napoleon in the fundamental
cause of rebellion, its perceived end and its actual result.  This is something that in
either form Napoleon strikes down with intensity and force, as seen in chapter seven
when Napoleon coordinates public confessions and demonstrates public execution in the
most brutal of fashion.