I'd completely ignored this show for a long time, mostly because the only exposure I had seen to it was some rabid fangirls. Recently saw an episode and decided to give it a go... which promptly turns into the wife and I netflixing the whole thing from Ep1.
I think the problem is if Sam isn't whining and being Emo, and they don't go "no soul" on him again then all he really is to the show is the person Dean asks things of when it involves using a computer. I wholeheartedly agree that they need to find a loophole to get Gabriel back on the board. Don't know how to write it in though. I also preferred loopy/mildly insane Cas.
In the back of my head I think the network will do their damnedest to get 10 seasons out of it, and hope that by then Arrow is reaping in the fans and they can cook up some more support shows.