He's not portrayed as a rock star. There's one song in which he's referred to (by people questioning him) as a "superstar", but he's not portrayed that way. It's actually a relatively thoughtful portrayal.
It is disrespectful.
That's what I thought. Then I watched it. There's nothing blasphemous or disrespectful about it, in context. Obviously Herod's song is disrespectful. So are Herod's words, as quoted in the gospel. It's an interpretation of the Gospel. You may not like the music, you may not care for the interpretation, you may not like the staging. That's fine. But the show itself is not inherently blasphemous or disrespectful.
(Obviously, the above is my opinion. I speak for myself, not for anyone else. If you want to tell me that that's my opinion only, don't bother - I already know that.)
So, if you are the Chris, yes, the great Jesus Christ
Proove to me that you're no fool
Walk across my swimming pool.
That still cracks me up.
Did you know that in the latest incarnation (I think from Broadway) Herod is played by Alice Cooper? Puts a totally different spin on the song. Otherwise the CD is teriffic.
Shalom.