What if the man with the eye patch was controlling the smoke monster from another station?
Flame...smoke...hmmm...
very interesting observation.
Also- don't forget what Danielle called Smoky- the "security system." What does a security system do, but protect something. I think Smoky is guarding some aspect of the the island's secrets, & because Eko was so strong in who he was & what actions he took in his life, Smoky viewed him as a threat, so he killed him. I think Eko's words to Locke were like a warning not to upset Smoky or they would face the same consequence.