Stupidity: Barbara and Adam can obviously interact with physical objects (the statue horse, holding the door shut, etc.) but when trying to scare the Deetz's they tried visual stunts rather than throwing or moving objects.
Suggested correction: Barbara and Adam are not aggressive, intimidating people. Maybe they could have thrown and moved objects, but that would be almost violent. They would rather try a few visual stunts, instead of possibly hurting someone and/or damaging something in the house.
I respectively disagree with this. One of the visual tricks Barbara and Adam tried was her holding a bloody knife over his decapitated body, that in itself would have been violent and aggressive if they had been seen.
Suggested correction: They first off didn't really understand how to interact with the physical world and secondly they didn't realise yet they were invisible.
I'm not sure the point of this correction because we see none of this is true. Barbara picks up a physical object and moves it without thinking about it. Then she looks at herself in the mirror with the horse and sees she doesn't have a reflection.
I have to agree. Even if Adam and Barbara couldn't be seen, the noose that Barbara "hanged" herself with or even the knife she was holding still should have been seen as they are physical objects and a knife, to the Deetz's, would be floating in midair and would probably scare them off.
Stupidity: During the wedding, Barbara slowly takes her time saying Beetlejuice's name three times, despite having previously done so immediately fast and instantly earlier in the film.
