For "The Lonesome Death of Jordy Verrill", I think that one would benefit of them going in a original spin and go Seeds of Extinction on us for the scare.
For "They're Creeping Up on You", I don't think that one will really need a scare. With roaches, you just need them everywhere and that can be a good freak out. Perhaps something on/in the floor to make it feel like you're stepping on them. (A crunchier version of the Humpty Dumpty scene in Scary Tales last year.) Though I can see them having the old man pop out here and there.
Also, I just remembered that my friend Ian really doesn't like insects, so any runthrough of this house is gonna' be fun for me and Hell for him. XD