Zumaya wasn't a bust at all. Zumaya failed because of immaturity and an accident. He played too much guitar hero during the playoffs so messed up his wrist/forearm (immature) and separated his shoulder helping his family move when a fire was moving towards their house (accident). You can't blame that on his ability to pitch and close games. If he didn't sustain those injuries we wouldn't even be discussing Rondon as our closer, Zumaya would be.
But that's my point. A lot can go wrong. Zumaya had one great season and he was in the less stressful 7th inning. He had closer of the future all over him, but as you described, a lot went wrong.
My point is, just because Rondon has the right stuff and throws hard, doesn't mean he will succeed. I just have a hard time throwing him into the closer's role as a 22 year old rookie. Have some been successful at that age? Yes, but others have flamed out. I just recall Zumaya and Ryan Perry having that "Closer of the Future" tag. For Zumaya it was immaturity and injuries, for Perry it was control and IMO lack of seasoning (brought up to quickly).
My point is when you go with a rookie closer, a lot can go wrong. I would be much more comfortable with Rondon in the 7th much like Zumaya as a rookie to relieve some pressure. Then go with Dotel/Benoit/Coke in the eighth based off matchups and have your closer (Hanrahan or whoever else they bring in).
That was the point I was making about Zumaya. And again, Hanrahan wouldn't be my choice. I would much rather have Gregerson and maybe their SS prospect Jace Peterson and whatever else we could get.