None of these cards except for Cartographer is weak. Cartographer with an added Peddler is likely too strong, Crystal Ball needs no buff, Duplicate needs no buff, the second Feodum variant is totally crazy, Monument being stronger than Plunder is totally crazy (not to mention the issue that a non-terminal that can be played as nothing but +2VP does not work; cards that provide VPs should lead to game progress and not to loops).
Except for obvious power level misevaluations (dude, Monument ain’t weak!), making cards more wordy and complex is seldom a good idea.
Take Pendant, a powerful Treasure with a simple and clear wording. Why mess this up via adding Treasure trashing or Loot exchange to it?