The Role of Blank Verse in Shakespeare

I was giving some thought to the way Shakespeare uses language while reading 1 Henry IV and I noticed something a bit unusual. If my memory is serving me correctly through most of the plays in which there is a king present the royal family almost always speaks in blank verse. It gives a certain air of formality to their speech, and elevates them among the common people. It is usually the fool, or common people who speak in normal prose. For example in Richard III there are hardly any common people in the play, and no fool. It's a very serious play about the lives of kings, dukes, and other noblemen and women, and as I was scanning it over I noticed that (I think) the entire play is written in blank verse. In Hamlet it is only when Hamlet starts pretending to go (or perhaps just has gone) insane that he starts talking in normal prose. I believe up until that point he talks in blank verse, which adds to his royal status. In fact, as I was scanning over the play a little more I noticed that it is only when he is acting insane that he talks in normal prose. When he is talking to Horatio, or even berating his mother, or when he is giving one of his famous soliloquies it is in blank verse. This is because Shakespeare is using normal prose as the language of common people and fools, and it is only when Hamlet wants to be considered a fool that he talks like one (though this is only one of the tactics he uses; his incessant wordplay is also typical of the language of fools). Knowing this I started to pay close attention to who uses blank verse and who uses normal prose in 1 Henry IV and I was surprised by the results. Obviously King Henry and his noblemen use blank verse (that is to be expected), but it is the fact that his son Prince Harry uses plain ol' normal prose that is most surprising. Being a member of the royal family one would expect that he should use royal language, that is blank verse. He doesn't. Shakespeare obviously did this intentionally, and I think he was giving one hell of a political statement by doing so: he's insinuating that Prince Harry is fraternizing with the common folk too much, and is a drunkard and a fool. That's not too much of a shocker, considering what Prince Harry is portrayed like, but Shakespeare doesn't even have him talk like a member of the royal family. Prince Harry is treated by Shakespeare as just an everyday, average, layperson instead of as nobility. The heir to the throne is nothing but a fool.