I will look into all of those concerns as soon as possible. These all seem like bugs, so I will try to find them and patch them out ASAP. I will keep you updated :D
For the stock trader, there should be a button underneath where you hire them that gives info about how it all works.
For farm orders, it is more like comparing if it is worth buying certain crops at bulk.
Thank you so much for the feedback!
EDIT: A new update has been pushed out fixing all of these bugs!