I have been to Eastern Rite liturgies that routinely last nearly two hours, with half-hour homilies that are so enlightening that you forget what time it is. I remember in the Episcopal church that, however long the service lasted, nobody would dream of walking out or complaining about it. If the recessional hymn had seven verses, everyone would sing them all loudly.
Unfortunately there are some Catholics who believe that it is written somewhere that a Sunday Mass cannot last for more than an hour. If it does, they will generally do one of these things: A. Get up and leave after Communion, usually in an manner obvious to the priest; B. Complain loudly to the priest when Mass is over; or C. Fire off a petty letter or email to the priest about his lack of consideration for letting his Mass “run over.”
One suggestion I have is to remove all clocks from the nave of the church and, if your church has clock bells, disable them until Mass is over. As for singing, on a Sunday Mass, everything should be sung, with the Mass parts (i.e. Gloria, Sanctus, etc.) having first priority. There should also be adequate periods of silence without “filler music.”