Concerning the proclamation of the Gospel from memory, I put your question to Father Thomas Richstatter, O.F.M., who teaches liturgy at St. Meinrad Seminary. He responded:
"I know of no official (magisterium) statements about this; I consulted other colleagues and they too know of no statements. The practice is not sufficiently widespread to bring about any official comment...
"The more important issues are not the reading vs. reciting on the part of the priest, bishop or deacon but rather reading vs. listening on the part of the congregation. Faith comes by hearing, not by reading, Scripture says."
A recent newsletter from the U.S. bishops' liturgy committee states, "Just as the Church is obliged to faithfully proclaim the Bible as it has been passed on, the reader is obliged to faithfully proclaim the biblical text exactly as it appears in the Lectionary for Mass."