I don't think Cage did that good of a job. If you got it, good for you... I didn't (and still don't after two viewings), it might have something to do with my admitted dislike of the actor.
I got the whole Adam West thing the second time I saw the movie. He was, obviously exaggerating the routine with the pauses. Having watched "return to the batcave," recently, I got the joke. It was supposed to be bad, because the Adam West dialog was bad, campy, cheese and sometimes over-dramatic, specially for a vigilante. Cage was, pretty much parodying West.
The movie does start with a "what if a kid decides to be a super-hero in the real world" plot, but switches, when Hit-girl is introduced, to fantasy.
The answer is clearly no, you can't be a super-hero because you will get you butt kicked, if not killed (Kickass). This was addressed and implied all over the movie. A super-hero stuck in reality could only get his ass kicked all over the movie. That would makes us laugh, at his failures, for the first half-hour, but not for 2 hours. There had to be a contrast, such as Fantasy.
A super-hero can only exists in fantasy (Hit girl and Big Daddy). That's when the movie takes the audience away from reality, where kickass fails, onto fantasy, were super-heroes save the day.
Red Mist, pretty much, shoves Kickass, hit-girl, Big Daddy, AND THE AUDIENCE back to reality, which makes one of them end up in the way a super-hero would end-up in the real world.
Hit-girl saves the day by taking the movie back to fantasy, where super-heroes can give an entertaining fight and win, specially an 11 year old girl who can reach the car pedals. The jet-pack scene is, pretty much, the last time the audience will be reminded of how Super-heroes can triumph in a world were they can operate iconic comic-book props from the golden age, which, BTW, are yet to exist in an efficient way. The jet-pack might as well be Batman's hand-held grappling hook/spear gun, or a Jedi's lightsaber. Fantasy.
At least, that's how I interpreted the movie.