One other thing to keep in mind is that not all cars going
to industries on the layout will be loads, and not all of the cars coming off the layout will be empties. It is not likely that you will have any cars that go to one industry on your layout to be loaded and then to another industry to be emptied. Typically a move that short will be more economical if done by truck. What you will have is some industries that make a product. That type of industry may receive raw materials in one type of car and ship out finished products in a different type of car. Other industries may be warehousing and receive inbound loads by train with outbound distribution going out by truck.
Break your layout down into individual industries and think about the traffic flow for each industry. I was unable to read the names of your industries in your original post, so I'm going to throw out some typical examples of industries.
Back in the 1980's the company I worked for was located in South-Central Los Angeles. There was a company right behind us that made tanks. I remember that they specifically made pressure tanks, to hold compressed air. Some of their tanks may have held propane, co2, or any other gas that an industry might use in compressed form. They may have also made fuel or oil tanks of the nonpressure variety, but I don't remember for sure. Typiucally about every couple of weeks they would received a couple of mill gons loaded with steel sheet and steel shapes such as angle iron, channel iron, "z" shape, etc. They would unload the steel and put it on racks for use, but the now empty gons would stay on the tracks. As they manufactured the tanks, scrap metal pieces would be thrown into the gons. Since the scrap was just thrown into the gons, it took a lot more space than the neatly stacked fresh metal. When they were ready for the next shipment of metal, the scrap loads were ready to go out. The railroad would pull the scrap loads out and put in fresh loaded gons for them to start the process over again.
A furniture factory might receive bolts of cloth, foam and/or cotton padding and hardwaqre in boxcars, plywood and dimensional lumber on bulkhead flats. The finished furniture might go out in the same boxcars that the raw materials came in on, but the bulkheard flats would go out empty. Much of the furniture might also go out by truck. L-c-l, or l-t-l is much cheaper sent out by truck, but if they had full car loads to go to a large distribution warehouse elsewhere in the country, they might use boxcars loads to send the furniture out.
A food distribution warehouse will probably not send out anything by train, but might receive car loads of product. Typically, boxcars loaded with can goods and bags of beans, flour, or rice. From the time of the advent of the interstate highway system until the mid 1980's to now, most perishables would have been moved by truck. With the increase in fuel costs, more produce has been moving by train, but mostly from a large cooling plant to another large refrigerated plant in another part of the country where it is distributed by truck. Tropicana sends 5 100 car juice trains to NYC weekly and I think two more to somewhere in the upper midwest every week, but they also have a warehouse in the City of Industry in Southern Cal where they send up to 5 car loads of "Tropicana Pure" in cases of bottles perhaps 3 times per week on U.P. trains from Bradenton Florida. Those car loads come in on a mixed freight. I'm not sure if they have a similar operation in other parts of the country, but they could have similar warehouses in the Pacific Northwest, or Northern California.
I would suggest that you start by putting on the customer's hat and figuring out what products you would receive by rail and what would be sent by rail for each industry. Then put on the railroad manager's hat to figure out how you would route those shipments in and out. Just play with your trains moving loads in and out of your layout, until you have an idea of how the layout flows. Once familiar with the flow, you can then figure out how to do the paper work, car cards, etc. You don't necessarily need to run trains on a schedule. Time sensitive freight trains generally run on a schedule, but often most freight is sent out in a train operated as an "extra." If the product is perishable in at least some of the cars on the train, it will be expedited, but not necessarily run as a scheduled frieght.