My Thesis is: "Overwhelming strength and power of a group can lead to thoughts and actions that one person alone may not have the power to resist...

I'm not sure what your question is, but your thesis is a
very strong one and one that can be easily supported.  We see quite a bit of the mob
mentality at work in the novel.  The strongest example of course is that of Simon's
death.  One individual boy would not have been willing to kill Simon, but because of the
fear and hysteria caused by the storm and the threat of a "beastie," the group commits a
horrendous murder.  Other instances of this type of mentality are Jack's hunters,
especially in the killing of the sow.   The painted faces result in a loss of individual
identity and a group mentality takes over the boys.  When Piggy talks Ralph into going
to Jack's group to ask for his glasses back, Ralph hesitates by pointing out that they
will be painted.

Individuals who resist the group mentality
are hunted, tortured, or killed.  Examples are Ralph, Simon, Piggy, Sam and Eric.  When
Simon confronts the Lord of the Flies, he is warned to "play" like the others.  If not,
they will "do him."  Because Simon cannot conform, he is
killed.

The book is a fascinating study of group dynamics.
 Approaching it this way allows you to explore aspects of leadership, rebellion, and
conformity.