Well we've never tried democracy without a monetary system, so we don't really know. Might work better without it. As for your last point, interesting a similar argument could be laid against capitalism. You cannot not participate, as capitalism in general relies on private ownership of property - and since all property has basically been apropriated, non particupation is practically impossible. Either you're free by work and ownership - or you starve.
You mean a the free trade system that pilgrims and native indians did? That could be good. It would highlight people's specialties and talents.