Again, this isn't about rules, this is about a preference.Then I go back to the fact that you're being overly-restrictive in your approach for no reason. I'd have to hunt through the PHB to get the exact wording but it explains there that sometimes a failed check just means you make no progress.
How are you worse off than if you hadn't tried? (Maybe there's an opportunity cost, but the above sentence doesn't specify.Not getting information that could be useful can be it's own penalty.
Yup. Agreed.Getting noticed even though you were trying to be sneaky is bad.
This is like your first example. There's also zero cost to trying. Again, at least according to that sentence.Not being able to tell if someone is lying is not helpful.
Turns are a precious resource. Have you ever missed and thought, "Drat, I knew I should have done that other thing"? At the very least, you could have taken the Dodge action.In combat if I swing my sword and miss, there is no penalty other than that I didn't do damage. Same here.