The next to last storyline mission in sequence 5 is actually the first homestead mission, which gets you the lumberer. At that point woodworker 1 and farmer 1 are available (the farmer one is on the frontier) immediately, but you have to advance the season in sequence 5 to make lumberer 2 available because its only available in the summer. Huntress 1 is available once you start sequence 6, but the rest of the missions require you complete previous missions.
However, I have no idea how they unlock after you've finished the game. They're supposed to be still available even after the game has been beaten.