If you go online, you will find out that Elder's text ONLY applies to choose one's and choose two's. Feel free to complain about the wording, it is what it is (I myself would probably give up on keeping the text at max font).
This is also implied through Donald X.'s preview text; if Elder applied to literally all abilities, then what does this sentence mean?
If I made a card like Elder as a regular pile, game after game there'd be no choose-one on the same board.
So Elder doesn't affect Barge, Jester, Border Guard, or even Duchess. It's only for cards like Pawn, Count, Amulet (for one turn), and Town Crier.
Two additional rulings that you can discover from online:
-If you Elder a Scrap and trash a Curse, you get no bonuses.
-If you Elder a Catacombs (and choose both options), you put the 3 cards you're looking at into your hand, then you discard those exact 3 cards and draw 3 new cards. (Catacombs is the only thing moving those 3 cards, so stop-moving doesn't apply here.) Yes it's weird, and would require an extreme edge case to be useful in gameplay.