"Praised be Jesus Christ!"
I suggest this as the typical sacerdotal greeting to people. In place of the trite "hello," "good morning," and especially as a response to the amorphous "how are you?" just say "praised be Jesus Christ!" And if they ask again, "how are you?" say it all the more emphatically "praised be Jesus Christ!" and by then they will usually get the point that you will respond kindly, with faith and leaving things (including your state of being) in the hands of the Lord.
You've heard of "keeping Christ in Christmas." Let's call this keeping Christ in every day.
That is how the Poles greet the priest and the priest greets the people, same thing in Italy, it's a typical Catholic greeting, "praised be Jesus Christ!" and the response is "now and forever!"
For "farewell" you can say as the Latin Americans do: "May the Virgin be with you!" "Que Virgen te acompañe."
We need to re-baptize our niceties.
Laudetur Jesus Christus!
In aeternum!