Q. 1. What is the appropriate time to break the Host during the Holy Mass? Should it be done during the Consecration or later in the liturgy during the "breaking of the bread." I have seen it done both ways and wonder if one of them is wrong.
A. 1. On this matter, the Vatican's Congregation for Divine Worship and the Discipline of the Sacraments pronounced itself in 2004. The instruction in "Redemptionis Sacramentum" states: "In some places there has existed an abuse by which the priest breaks the host at the time of the consecration in the Holy Mass. This abuse is contrary to the tradition of the church. It is reprobated and is to be corrected with haste."
To answer your question, the Host should never be broken at the Consecration. Such is contrary to the Church tradition.
As additional information, breaking the Host at Consecration does not make the Mass illicit.