… It's not the Official Latin that is being changed, which in turn is a translation from Greek [as it] was from Hebrew, if I'm not mistaken. … The more original Translation is "Forgive us our debts, etc", whereas now we say "Forgive us our trespasses".
Anent "if I'm not mistaken," I am afraid you are. The NT exists only in Greek, and to this Greek original and to it alone adheres the guarantee of inerrancy.
Anent "debts" versus "trespasses," see my last comment but one. The word in the most widely used English form of the prayer has been "trespasses" for at least 150 years. That is not to say, however, that someone who privately prays "debts" rather than "trespasses" or "today" rather than "this day" shows disrespect to Our Lord, let alone blasphemously adulterates the prayer.
Note, too, that in verse 11 of Matthew, the Vulgate uses a word,
supersubstantialis, where the familiar prayer, following Luke, uses
quotidianum. In most bibles there is in this place in Matthew a translator's note on the text explaining that (1)
supersubstantialis appears to be a coinage, not a standard term or even a word found elsewhere; (2) the Vulgate's use of the term in Matthew is largely inexplicable because the Greek word it translates is the ordinary Greek word for "daily" and is
exactly the same Greek word used in Luke, where it is translated as its standard Latin equivalent, the familiar
quotidianum; and (3) hence, while the precise sense intended by
supersubstantialis cannot be determined, it is likely that
supersubstantialis is meant to signify
just what
quotidianum does: something routinely needed in daily life, not something special or luxurious.