A few minor things:
Carrier: It should say "If no-one else does, +
." to mirror Tournament.
Nightwatch: Attack should be capital, see Squire.
Iron Maiden: It should say:
If yours is an...
Action card, +2 Actions
Treasure card, +
Victory card, +2 Cards
Each other player gains, if theirs is an...
Action card, a Ruins
Treasure card, a Copper
Victory card, a Curse.
Hospital: Like carrier, it should say "If you do, +1
."
Hunter: "Mat" doesn't need to be capitalized.
Investor: "Coin token", not "coin token"
Assemble: Right now it's not clear that you gain a card costing up to
more than the trashed one, it could easily refer to the Copper.
Blessing: The +Buy should be moved inside the "Once per turn:". See the new Borrow.
Parting, Bargain, Sherrif: "Token" shouldn't be capitalized.
Magician: The "()" aren't necessary.
Harm: It should end with a period, not a semicolon.
A few other optimizations that aren't as necessary:
Decree, Research: It could say "onto" instead of "on top of"
Sunken City: It could say: "it's" instead of "it is"
Nightwatch: "Players other than that one" would be clearer I think.
Sultan: This is shorter:
You may discard a Victory card, to gain a Treasure costing at most the same onto your deck.
Well: It would be nice if the text was nudged up a bit.
Hospital: "Gain a Copper to your hand" is shorter.
Hunter: See Well.
Assemble: "Putting them onto your deck" is shorter.
Inquisitor: The first
symbol is really off center. Maybe delete one of those spaces.
Maze: See above.
Necromancer: You could nudge the text up, "Zombie cards" can just be "Zombies", and "is not" can be "isn't".
Incantation and Farmer: I think it should be "into your hand" instead of "in your hand"
Purity: Maybe change the text so it fits more.