Hmmm. I'll have to think on this for a while.
On the one hand, if one is going to legitimize compulsory government and police, then its going to be a little hard to justify restricting those police from asking certain voluntary questions.
On another hand (hey! Vishnu has more than two!), why not restrict police from asking certain questions? We've plenty of reports of police using commanding or authoritative tone of voice during a supposedly consensual encounter. Why not restrict those police who deliberately use difficult-to-prove tactics?
On a third hand, why not err on the side of liberty, and close the door to some police who don't use judgement, but just a "standard, one-size-fits-all" tactic knowing that some one will waive their right to silence (or don't even know they can apply it) to get a "freebie" arrest?
Hmmm. I'll have to think on this for a while. In the meantime, I'll approve anytime compulsory government limits itself.