The formula is to find a height that lets you keep your hands above your waist when working. Bend your arms with your elbows at your side until your hand are parallel to the floor. That should be a good height to start with. If you have a kitchen counter that you like you can use that height. You can always use chocks to adjust the height, or make a stand for a wedging bat or work board. I made one out of 3/4" pvc pipe for a very tall cook to put his cutting board on.
If the table is too tall make a step out of plywood that is the right height for comfort. Be sure to put nonslip tape on the top! Most step stools will be too tall and will have a tendency to slip when you lean over the bench.
These are the backbone of my professional life. The perfed trays are pretty lightweight. You would be better off cutting plywood to fit the rack. You could put some wire grating on top for better air movement, or wrap the boards in canvas. The useable area is about 2" narrower than the rack if you are doing anything taller than the spaces between shelves. They are available with different shelf spacing, so think about the size of the stuff you want to store/dry. The zippered vinyl covers are good at holding moisture-I used them as makeshift proofing racks by adding a pot of boiling water at the bottom with my product at the top. If you keep your wares about a foot from the bottom of the rack you can put in a water pan underneath and it should hold enough moisture to keep things leather hard for a while. You will have to experiment with your local humidity. Get the heavy duty ones and they will last for a very long time. Be nice to the casters or they will get tricky to steer and kind of jumpy, and that could mean stuff falling over or cracking.
You can run a small heater or dehumidifier near your molds, which will help them dry. We let larger pieces sit until the wall-the solid layer next to the mold-is about 1/4" thick before pouring off the excess.
Pinholes can be caused by dirty molds. Older molds often leave pinholes, as the plaster has started to degrade with use. If you are using old molds, you may have to recast a master and recast the mold in new plaster. Most of the time a damp sponge or chamois will take care of them. If the top of the piece is plugged with semi-solid clay, you can poke it with a dowel or small sharp knife, then pour out the excess slip still inside the mold. Pieces with small gates (pour holes) often need this, especially if the rest of the piece is broader, like a tree mold will be.
The many variables of slip viscosity, temperature, mold dryness, air humidity, etc.,etc. mean you need lots of practice to gauge your cast pieces readiness to be pulled. Be prepared to experiment until you have a good idea of how the slip will act. You can reclaim your clay.
At this point you are in training to learn a new trade. You could be in school learning to be a nurse and have the same issues. With that in mind, is there a studio in town where you could work part time? The exposure to others working methods is valuable in itself, and if they can't pay cash, perhaps private lessons or free clay or some exchange could be worked out.
Also, decide for yourself what's really important to your family life and let the rest go. Home made dinner is nice, but it's time eating together that's more important to me. Adding layers of stress because society tells us to be "doing it all" will just drive you nuts. Kids really can amuse themselves. They will still thrive even if you take the time to clean. And a clean workspace equals better working habits, which means more money when you are trying to sell in quantity. Also, you can have them help with the chores-it builds character!
I use this as a selling point. I have a bit of schitck were I describe how beakers thousands of years old exist, and that the beaker they purchase today could be found by the archeologists of the future....it works pretty well, too!
This is like the question of how to have a "bikini body", which is answered by having a body, and wearing a bikini. Take the vessel you made, add dirt and seeds and you have a planter. Drill a few holes in the bottom if you really want to.