The basic idea is that every dwarf is free to practice the profession of their choosing and none are forced to learn a new craft. So you can choose the professions for your starting 7, but once the settlement is begun, no labors can be changed. Dwarfs can practice only those labors they come from the mountainhomes already trained in - and all dwarfs must be given the opportunity to practice their profession. Top priority must always be to try to provide all dwarfs with the workshops and resources necessary to work in their chosen field.
This can also be interpreted as labors requiring actual training and education to master - not something any dwarf can just figure out as they go - and since the fortress doesn't have any educational facilities other than military training, dwarfs are stuck with the skills they already have when they get there.
As a further challenge, no nobles can be appointed other than broker, bookkeeper, and manager (all of whom must already have some skill before being appointed), to maintain the egalitarian aspect of this personal freedom commune. Any offers to increase the status of the fortress should be denied. If a noble is automatically assigned, like a mayor, it is only to appease the monarchy of the mountainhomes, is nominal only, and any requirements for this position must be ignored.
The only change the player can make to labors is to draft those who already have military skill to form a militia. They must be given the weapon they are trained in, however.
I'm thinking of starting a community fort following these guidelines. Think I can pull it off, as long as I choose my starting 7 carefully? Anyone else want to give this a try?