I really think Austin's character is just him being awesome. The Stone Cold gimmick turned into something totally different in the WWE which would be McMahon's creation. In ECW and in his early WWF stuff it was mostly just Austin improvising. Turning him into a superhero was all McMahon.
I think Benoit and Malenko had a couple of "nothing" matches in WCW and other indies before ECW.
ECW was, of course, what made them famous. Well, got people's attention.
As for Austin, I think Heyman said it best when he said they "turned on the camera, and told Steve to just say what was on his mind". So yeah, it was just Austin being awesome. Credit to ECW for LETTING him, though ;->
Jericho's first title in the US was the ECW World TV Title. Just watched the episode from 1996. Joey Styles made the (now obvious) comment of "He (Jericho) WILL win MANY more world titles in his career". Amazing how "raw" Jericho was then ;->