Executor's responsibility

If a will exists, can the executor choose not to execute it? Also, who has a right to request a copy of the will?

The executor can not legally disregard it. For example if it leaves the executor 25% but the executor would take 33% without the Will, she can't say "heck with the Will".

It really depends on your state's law. In some states the failure to turn it over is a Felony.