Huh, I just noticed that I'd missed this question by Klaus completely when he posted it last fall. Better answer it late than never, I guess.
The answer is simply that yes, you have to include everybody present in the soft place. This means that most shamans will be unable to impose this shift in realities on anything more than a handful of people. You don't have to pay for crows or other animals, however
Of course one could create a Secret that'd get over this observation effect (that's what it is - observing persons are harmful to soft places) somehow, or perhaps figure out a way to gain massive amounts of Pool from somewhere to pay for pushing the whole village into the dreamworld. One could travel north to learn the ways of ritual magic from the Gorenites, for instance. Even better, a suitable totem willing to loan you a couple dozen/score/hundred Pool points from its immense Pool would do the trick as well...
I wonder in hindsight why I've written that Secret in a way that implies that you'd need this specific Secret to fall to sleep at the drop of the hat. Seems to me like that part should be doable without such a large investment in dream shamanism - a simple Ability check might suffice. Probably has something to do with the "can't be awakened before he wills it" thing, which is potentially pretty useful for dream shamanism. Strange.