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.
But they weren't violent and aggressive. They weren't threatening violence or aggression to anyone. They didn't commit an aggressive or violent act in front of anyone. They were just trying to scare them, just like wearing the sheets earlier.
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.
Stupidity: If none of the Dietz (aside from Lydia) can see the ghosts of the Maitlands, why were they hiding out of the window when they went up into the attic after Delia's critics left? They could've been standing there in plain sight and none except Lydia would know that they were even there.
Suggested correction: They didn't know who could see them and who couldn't at that time.
Stupidity: Juno adamantly warns Adam and Barbara against getting help from Beetlejuice, but then proceeds to freely tell them exactly how to conjure him. She even snubs them when Adam asks how to get back in touch with her should they need her assistance again.
Suggested correction: I think she was giving them more of a warning against conjuring him accidentally by saying his name three times. Didn't she tell Adam that she wasn't available when he asked? That might explain the snub.
If she was warning them about accidentally saying his name three times, then it also would have been wise for her to tell them in that same moment that they could make him go away by saying his name three times again, but she didn't. She also said she wasn't available to help them in that moment, not at a later date like Adam was asking. By refusing to answer Adam's question, she made it more likely that they would turn to Beetlejuice for help.
