If you want to focus on heavy discard - i.e.: keeping your opponent's hand at 0-1 cards - then I would recommend Shrieking Affliction as it will punish them for having so few cards. Definitely go for Raven's Crime, especially with Dakmor Salvage as you can keep discarding salvage to cast over and over with dredging. I play a discard deck and this is really effective. Wrench Mind, Delirium Skeins and Augur of Skulls are all nice. Dinrova Horror seems pretty mana-heavy for what it does. You could put Victim of Night in for a quicker, cheaper way to clear most threats. With Raven's Crime and Dakmor Salvage, what about Rotting Rats?

Haunting Hymn costs waaay too much mana. I'd sub it and maybe a few charms out for a set of Wrench Minds. Other than that it looks like a sweet deck!

The more I have playtested, the more I agree with at least taking out Haunting Hymn for Wrench Mind. The original concept (and the reason I like the charms so much) is that they are an instant speed discard, which means you can use it at the end of their draw step and prevent most cards from being played. Haunting Hymn is still instant speed, but it's far too expensive for what it does, and 2 Wrench Mind seem much more appropriate.

Fog Bank makes excellent stall.

That is a really simple solution that I totally overlooked.

I would also up the a 3-1 split of Duress and Despise. You've got plenty of removal to handle creatures, but very few ways to deal with instants and sorceries that could cause a lot of trouble (any number of destroy artifact/enchantment cards, for example).

Also, since you are in blue, you have access to some great tempo.

Echoing Truth is much easier to cast than Boomerang, and can send tokens or planeswalkers away. Spell Pierce and Countersquall are both solid options, as is Mana Leak. Turn Aside and Swan Song are both interesting as well.

Delver of Secrets  ^Flip is only good if you can keep it alive with counterspells.

It's true. I haven't had a ton of luck with it yet, but it has absorbed some lightning bolts that would have hit my face otherwise, and I have traded with a few swiftspears for it.

Two suggestions would be Nezumi Shortfang, and its flip, which adds more rack effects, and Dimir Guildmage, which is both draw AND discard. Both are fun in their own way.

Pack Rat is also always a great choice

Great deck to you as well might i suggest Bile Blight for token deck or just rid of a pesky creature as well as Go for the Throat

Considering Murderous Cut and/or Tasigur's Cruelty to take advantage of Delve as a way to make my spells cheaper. Even if I still end up paying CMC 2, both are stronger than their alternatives Victim of Night and Wrench Mind. Cruelty also doesn't target, so it gets around Leyline of Sanctity. Definitely looking at Bile Blight!

Necrogen Mists is kind of a budget Lili and if you have multiple out it's just oppressive. You need to mainboard Raven's Crime and Despise needs to just be taken out completely. Too situational especially in modern. Turn Aside is pretty much useless in this deck as you have nothing you should really protect. Delver of Secrets is close to useless. You need to run 4 of Wrench Mind and Duress. Blackmail could help you a lot more than Despise. Inquisition of Kozilek is currently about 5 USD each and would help this deck significantly. Some Pack Rats would work better than Delver of Secrets  ^Flip.

Someone pointed out to me that completely cutting creatures from my mainboard means a lot of their removal are dead cards. Given the recent suggestions I've gotten, especially about Despise, I've done some revamping.

Raven's Crime is great, and has a FREAKING FLAVORFUL NAME :D

Try playsetting the murderous cuts. From someone who runs. 8 rack getting 4 cards in the grave yard is not difficult at all.

With something like Wistful Thinking I would suggest trying to fit Liliana's Caress in this.