Can you cancel the “cut” command in the orchard

Villagers will only marry and produce children if there is an empty home for them to move into. That is, there can only be one pair of villagers producing children per house. As homes start to become available as your population dies of you will begin to see a growth in your population, but it'll eventually stop growing again since the villagers will just run out of empty homes again. If you want your population to continue to grow you'll need to continue to build new homes for villagers to pair off into and begin families. Be careful, however, since building too many homes can lead to your population growing faster than you can produce food and other resources to support it.

Well like you said, Farmer is 1 of them. They will only do their farming from early spring to early autumn. Besides that, traders only do their job when a merchant is present. I personally keep the farmers on their job at all times. And take the traders off their job once there is no merchant in sight.

Finding the right balance for your farmers/traders in the "off-season" is really dependent on where you need them the most. If you need food, give them a gatherer job. If you need buildings send them off building.