I like your deck idea, but I find it funny you don't like the courier. That creature is usually seen as a favorite from ramunap red as it can help restock the hand sometimes. I do understand reasons for not enjoying it though, so I can see potential for replacing it with the cards you have chosen since you are splashing for black.

Best of luck with the deck.

It generally dies way too quickly. That's my main problem with it.

Deck looks cool Doomfall might be more useful than Duress since you can still use it if their hand is empty. I used to run Duress out of the board but found it to be a dead card too often

It's in sideboard for control decks where it is never a dead card. The only time Duress is a dead card against control is if they have no cards in hand and if they have no cards in hand then they're effectively already dead. All Doomfall would do is just allow me to occasionally get a Torrential Gearhulk or MAYBE a Scarab God.