Funeral
Action - Attack
Cost: 5$
+2$
Each player (including you) reveals the top 2 cards of their deck and trashes a card that you choose.
This is way too strong. It's so much more powerful than Saboteur it's not even funny. You could change it so that instead of the Attacker picking the card to trash, the victim does, but even then I think this would be too strong, considering its +$2.
Exorcist
Action
Cost: 4$
+1 action
Look through your discard pile and trash up to 2 cards costing 2$ or less.
This seems pretty good, though you probably don't need the $2 or less clause. It might be a little underpowered, even then.
Coffin Maker
Action
Cost: 3$
+2$
+1 action
You may trash a card form your hand.
As noted, this is strictly superior to Silver most of the time. You could give +$1 instead, but that might make it too weak.
Cantor
Action - Attack
Cost: 5$
+1 VP
+1$
Each other player gains a Curse.
I like this card. I suspect it is balanced, though quite strong. A VP-giving Witch that turns into a worse Monument. Pretty cool.
Graveyard
Victory - Reaction
Cost: 3$
Worth 2 VP.
When you buy this, trash a card from your hand.
When you would gain a card, you may reveal this from your hand. If you do, trash that card.
You have a lot of cards in this set that trash for no benefit. I would consider revising some of them, just for the sake of cutting down on similarity. Think about how Salvager, Remodel, Remake, Apprentice, etc., each do something different with trashing.
Crypt
Action - Victory
Cost: 4$
Worth 1 VP.
+1 card
+1 action
Look through the trash pile and choose a card costing up to 8$ that is not a Province. Gain a copy of that card. If the trash pile is empty: +1 card.
This is sort of a weird one. In a Kingdom with no trashing, this would be ridiculously strong--strictly superior to Laboratory, and cheaper! With trashing, I'm not sure it's very good. Rarely do you want anything from the trash, and people will be reluctant to put anything worthwhile in the trash. So this would become sort of just a Great Hall.
Lost Diary
Action
Cost: 5$
+1 action
Reveal the top 4 cards of your deck, put all revealed action cards into your hand, discard the rest.
I like this one. You would have to play test to be sure, but it's probably very strong. If 2 of your next 4 cards are Actions, you are essentially getting a Laboratory that also discards your non-Action cards (which is usually a good thing).
Cool ideas!