Hi, BuciferColor, thanks for your comment. The bug you mentioned regarding the bag pack being dropped out of bounds definitively needs addressing and hopefully will be fixed in the next release.
As you noticed, Frenni has a few tricks up her sleeve. If you try to jump up and down the stage to confuse her while she is chasseing you, she will jump down to you instead of using the stairs. Likewise, if you try to close a door while she is crossing it, she will walk through it (this last is done mostly to prevent her from getting stuck in the map geometry when she opens doors herself) but some that behavior may need some polishing too.
Despite the effort put in the optimization the game is quite heavy on the GPU. The intractable objects should display a white outline while you hovered the crosshair over them, but perhaps the shader that does that is not being rendered. Is hard to know the exact cause but given how far you have to crank down the settings to get the game to work, is no supersize that something got glitched down the render pipeline.