WillsHub is a legal information site on Australian succession law.
There is no requirement that an executor must accept the executorship role. But relinquishing it should be done as soon as practical.
The legal formalities to make a valid will require the will-maker to sign their will in the presence of at least two people who act as formal witnesses to the event. Signing a will in front of witnesses fulfils a protective function.
A codicil is a short document which makes a minor change to an existing will.
“Issue” is a legal term meaning all descendants including children. It is not limited to just children. However it can be a flexible term. But if using the words “issue” and children in a will it is important to clarify what is intended so as to avoid unintended consequences.