Agree with you on first statement. It wouldn't be easy for Canonical to deliver.. But as a backer, you could always cancel your Ubuntu edge if you was unhappy with something.(at release, not during campaign)
Related to jolla. You can do lots of stuff to be seen and heard without spec or finalized product, just look at Canonical. I don't want or expect jolla do make promises they can't deliver but sou can do so much to boost the brand and recognition. It won't cost you much, post stories, video blogs, do interviews, start some kind of countdown, post a post one every month on a few selected forum to show intresset in you customers, Web pages/updates that makes blog to write about it... Lot of stuff can be done almost for free. It's a one man mission. Let hope jolla doing well in the end.