@CopperCoyote A fleet is chosen randomly each day, and the resources are checked for it that day. This might change later, we'll see. I'll look in to the crew costs, I have an idea as to why it might be doing that. As for the fleet spawns, yeah the fleets require the ship to remain in the inventory for the fleet. You can pull the ship out later, but the fleet will not spawn that ship anymore until it's put back.
@Chronosfear Fleets won't spawn unless you have the amount they need + the amount of crew your station needs. (Their is also a way to prevent trading convoys from selling resources you need as well, not that trading is in yet :p)
@Runoved I really want to add that in, or use the Price Changer, or do some sort of trading myself. The only thing that is stopping me right now is that nobody has figured out how to dynamically change the price of the most important resources: Supplies, Fuel, and Crew. I can live with crew being stuck, but it just would not make sense for supplies to not also change price with their raw materials for example. I'd rather have nothing than have half for the final release.
@Azmond There are no industry skills yet. This is being remade, those will be one of the later features before full release.