Even as someone who has not utilized these freelance jobs in quite some time, this positive response is great to see! Especially the idea of "job groups" is amazing. I remember when I first joined this server and started out with some freelance jobs, the lonely trucking/driving a postal van is something I did not find enjoyable. To be able to do this with another worker while sharing the same reward is a great way of boosting player interaction, especially for new(er) players.
Perhaps it would also be an addition to have generated orders for the Post OP (#8 in OP's list), as this suffers from the same problem as the Trucker job does.
Also, it could be worthwhile to balance the system out. As OP's post indicates, some jobs simply pay more than others on a $/hour average basis due to the nature of the job vs. the reward. In my opinion, it would be great to see more variety in this.