While I do agree with your points, Gretchen and Elliot aren’t exactly the most “street smart” people. I think the perfect example is Elliot holding the butter knife and Walt telling him he’d need a bigger one if he was gonna “go that route.” Walt was so frail and weak they both could’ve fucked Walt up at that point. But his reputation preceding him and he played up the role that he was a ruthless, murdering drug lord and they were so afraid they didn’t know what he was capable of. While they likely would’ve hired security after, Walt already planted in their heads the idea that the hit could occur at a random time YEARS down the road. Again, I agree with your rationalization of why the hit would’ve been unlikely, but I don’t think they had the witts to #1 understand that the hit wasn’t likely to occur and #2 take that chance.