BRG's interaction (Requiting Hex, Stir Up Trouble) and its noncreature engines (Lively Dirge, Obsessive Pursuit, The Misty Mountains Cold) are all noncreature spells, so Duress proactively strips them from their hand before they can use them. Duress can't take creatures like The Sackville-Bagginses, Smaug the Magnificent, or Wolverine, Fierce Fighter, so don't expect it to answer their threats. Strategic Betrayal stays in the sideboard: the opponent chooses which creature to exile, so they can give up a cheap creature like Greedy Freebooter or Callous Inspector instead of their big threats. Erode only hits creatures and planeswalkers, so it does nothing against much of their deck, such as Lively Dirge and Obsessive Pursuit, and it hands them a basic land, so it's cut. Essence Channeler is a small 2/1 that Requiting Hex kills easily, so it comes out for proactive disruption.