[Acuracura]

A) If the item was seized it would have to be for a reason such as for evidence. Maybe you're confusing a radar detector vs a Jammer?

B1) If the item is not being seized but you're just handing it over to Police, there should be a Relinquishment of Claim with it. You will be signing a piece of paper or his notebook saying you're giving it to Police on your own volition.

B2) Depends on how the intimidation is used and what it leads to and in what context. In your case of a road block which is checking for driver sobriety, I would say it's fine. The cop is intimidating you to determine if you have already drank alcohol. If you have, the offence was already committed. Just because he was intimidating didn't make you more drunk.

If you excuse was: "The officer was very intimidating to me so when he asked if I had anything to drink I felt obligated to say Yes". Then the officer does an ASD and showed you had consumed alcohol anyways, intimidation will not be a factor.

Another example of you going through a road block:
Officer: "Have you had any alcohol tonight?" (In a intimidating manner)
You: "I have child porn on my cell phone!" (scared shitless)
I don't think the inimidating factor would be an issue after you get arrested

Different scenario: You're a suspect in a murder. Cops come up and take you down at gun point. One cop is holding a gun to your head asking if you killed whoever. You answer "YES". Now intimidation is a factor, especially because it led to a confession.