Aside from the head-slappingly wooden line-delivery on all counts, this trailer starts off (relatively speaking) pretty strong, delivering some of its most uneasy suspense early on, before it shifts from light colors to dark ones and starts doing that thing where it zooms in several times in rapid succession (what emotion, exactly, is that effect supposed to evoke?). Observe the subtle hate dripping from Rebecca's expression at 0:39, for example, or the creepy cat look at 0:33. Except that stuff doesn't really make any impact, because there's bouncy pop music happening in the background and the trailer is not yet focused on how Rebecca is creepy.
That doesn't happen until exactly 0:53 -- and I can name that exact second because this trailer has no area between "not enough" and "way too fucking much" -- do we really need the stabby drum-and-violin sound every time Rebecca looks at something? Do we really need that strobey ultra-fast-cut thing over and over, that we might know that there is something menacing going on here?
On the other hand, nevermind. There isn't much menacing going on here at all.