There are twelve of us, Sire, and I place all the resources of my people unreservedly at your Majesty's disposal.
So, if the Elder acquires a new missionary from a Faith card, is the new missionary placed in the Elder's location or in their region?
The Elder's location. The only time the Faith card you play allows you to do something in the region is if the card actually says "region".
And if a Trial causes Stops to be placed with no further notation, do they get placed in the Elder's location or their region...?
The Elder's location.
...and what happens if the Elder's location already has that Stop? Does the new Stop stack in the Elder's location, or does it not and then go to another location in the same Region?
They start piling up in the Elder's location!