Here is my response.
Great paragraphs here. Regarding the music-->acting careers, Will Smith and Ice Cube are two good examples. They can switch back to music whenever they get inspired (maybe Will Smith will have problems these days). I've always thought hip-hop and country guys can more easily cross over, because their audiences think their music persona is really them. Their lyrics are about their "real life" (supposedly). Pop and rock stars have a more difficult time becoming film stars, because their music audience sees them as an act, or an artist. Just theorizing here.