Well I guess we'll never know how things "would have" played out, but I still believe that Mantha had a zero shot at making the Red Wings out of camp, therefore Mantha's injury has no barring on whether or not Jurco makes the big club. In my opinion the only thing that will keep Jurco down to start the season is if Alfredsson is ready to go on October 9th against Boston - I hope he is.
I agree with your sentiment, but I don't think there was zero chance. Its all irrelevant now, but I feel that if he had truly shown he was ready - by tearing it up in preseason games - Babs would have asked KH to find a way to have him on the roster. And in that way, that's why I feel it had a potential impact on Jurco's making the team or not.
As for Alfie, unfortunately I can't see him starting the year with the wings especially as he isn't coming to camp. I reckon it;s more likely that he signs around December and plays half a season, assuming his back holds up. It's not like he'll be out of the state and its make the team or go home, now that his family is in Michigan.