If you want vitrification, make a cone 5/6 crater glaze. Adding silicon carbide will cause cratering in many glazes. Use a really fine mesh, like 800 grit, which you can get from lapidary supply stores online. A good starting point is 0.5% by dry weight.
The large splash pan will keep your studio MUCH cleaner, which is why I don't like the Prodigy. That little pan isn't nearly as good as the big pans on their other models. The built in one-piece aluminum pans are the best. Super heavy, super sturdy. The TS wheels do not have a drain hole or cleanout door, nor are they necessary. You just pop off the wheel head and scoop out the trimmings and sponge it clean.
On some glazes that are low in clay, when the glaze completely dries the wax will peel up since the glaze is too powdery to prevent it. I have a couple that do it. When it happens, it peels up the glaze with it and ruin your nice glaze job. To prevent that from happening, after you're all done glazing the pot and before the glaze has totally dried, lightly go over the wax with a torch to melt it into the glaze. Works like a charm. Or put the pot into the kiln and start the firing right away.
I would build a crate rather than trust cardboard boxes on a pallet. It's not uncommon for the shippers to hit the boxes with the forklift, or to set other things on top. To guarantee that they would survive shipping on a pallet you'd need to pack them as well as for shipping via UPS, and that will waste a lot of space and packing materials. With a good solid plywood crate you won't need to pack them nearly as well since the odd of them ramming the forks through the crate are pretty slim. Plywood sides with 2x4 corners is almost indestructible. Do you have to send your own tables and canopy and all that, too? That would be a lot of crates....
Check on if there's a price difference between a pallet or a crate because of size and shape, and if there is then build a crate that will fit on a pallet. If you need to supply your own pallet then go around to the backs of strip malls or business parks and you should be able to find one that someone is getting rid of. I always just leave my pallets out by the dumpster and someone takes them away.
BOTH! Shelves on top of tables. I like this setup because it's easier to level tables, I can store all of my under the tables after unpacking, and it gives me a lot of options on how to display my work. I can show large pieces, small pieces, stacks of bowls and plates, platters on stands, really tall jars, etc. And it all folds flat. I fit this entire display and canopy in my Nissan Pathfinder. It consists of two 4 foot tables and two 5 foot tables. For smaller shows I can just set up the 'L'.
Throw it out and make another one. S cracks are a part of pottery life, and should be expected from time to time. It cracked for a reason. There was something done wrong during the making process, and the crack is the result. Figure out what it was, throw out the pot, and make a new one without a crack. It's better to learn from the mistake and improve your skills than to waste your time trying to hide it.
Try going over it with a grinding disc (lightly). Could be there's a thin layers of something on the shelf preventing the wash from binding. The grinder may also make the surface a tiny bit rougher, allowing the wash to grab better.
You can get away with a lot with small, thin pieces like mugs. Plates, platters, large bowls, lidded jars, etc, all absorb heat and cool down differently, so you may run into problems there. I usually open my kilns at 300F, often bisque fire on 'Fast Glaze' (4.5 hours), and put just pulled handles into the kiln for fast drying, and that's all with porcelain. The problem is not the speed at which things happen, it's the evenness at which things happen. I can't dry out just trimmed oil bottles in the kiln because they will S crack, because with closed forms the inside can't dry as quickly as the outside. I won't bisque fire a stack of plates on 'Fast Glaze' because some will crack since the middle of the stack won't heat as quickly as the edges. I won't fast glaze or fast cool a 15 pound lidded jar because it's thicker than a little mug and won't heat or cool as evenly. I'ts good to know that you can push some things when you need to, though.
It's not necessary to prop the lid. Just leave the top peep hole open and you'll be fine. Propping the lid is bad for the lid, and bad for the top rim of the kiln body, and totally unnecessary on kilns with decent switches. The only time propping is necessary is on really old kilns that just have on-off switches (light switches), where propping the lid slows down the firing so things don't blow up. But with low-med-hi or infinite switches it's easy enough to do a slow start, and the top peep will vent out the moisture and fumes just fine.
You should be using a vent if the kiln is anywhere near a living space.
When you say cracking, do you mean the surface of the lid is cracking and flaking off, or the bricks are cracking apart? Surface cracking and flaking happens on old kilns. The best you can do is scrape off any loose stuff and go over it with some thinned out kiln cement. But even then it'll just keep happening. You ca put a kiln shelf at the top of your load to protect the pots. At some point the lid needs to be replaced, or flipped over if the other side is in better condition, or swapped out with the floor if it's better.
The modern hinges are nice, and much easier to lift the lid on a kiln that size. They're not hydraulic, but spring loaded. Retrofitting is kind of a pain and expensive. A cheaper, simpler solution is to rig up a pulley with a counterweight above the kiln.
No matter who I'm teaching, their age, body type, etc, I first present my typical methods that work for most people, then adjust them as needed for each person if I see them struggling with those techniques and it's not just because of lack of experience. Every body is different, every muscle is different. Some people are really dominant with one hand, so that has to be dealt with. Some people have short arms, so that has to be dealt with. Some people have little hand strength, some people are obese, some people have no confidence, some people are too aggressive, some people move to slowly or too quickly, etc. There are techniques for dealing with all of it, and sometimes you just have to give the person permission to experiment a bit within the parameters of 'good' techniques to find which one works best for them. I stress all of this to my beginnings students, and try to make them feel as comfortable as possible, which can be difficult when they are struggling while the person sitting next to them is not.
As for obese folks specifically, or anyone with a body type that's outside of 'average', whether they be really tall or really short, I leave my instructions for body positioning a little more open ended, and instead focus on the goal rather than the specific technique. Instead of saying 'rest your elbows on your thighs', I say 'brace your elbows', and give them a few options, like 'thigh, knee, rib, sides, edge of the wheel- anywhere but out in the air'. That gives them permission to accomplish the goal within the limitations of their own body. Instead of 'sit with your stool all the way up to the wheel', I'll say 'sit so you can comfortably reach the clay, while reaching out as little as possible. Keep your elbows as close to your torso as you can'. As you watch them work, suggest techniques that play to their strengths, like coning with their fingers laced, which gives more leverage in the wrists and focuses on the hands rather than the arms, etc.
People know their bodies- they live with them every day. So if you just give them the goal and support them they'll figure out how to get there.
I make little 3/4 pound cups that I call juice cups or bathroom cups, but my customers call wine cups. I used to sell the for $10, but I upped them to $14 last year. They're an easy sell for folks who might not otherwise buy anything, or may not be able to afford one of my more expensive items. I've only got 5 minutes work in them glazed and done, so it's a good hourly rate. I think it's important to have something small and inexpensive in the booth, and they fill that need. I also make ice cream bowls (1 pound bowls) that I sell for $10 each. They are fast and simple, too. I raised the price to $13 last year and sales went way down. At some shows it worked, but at a lot they didn't. $10 is an easy number for people to justify. I also think that because ice cream bowls are the type of item where people want to buy more than one, that when they do the math it gets expensive quickly. Cups are something they're likely to buy just one of, but bowls tend to sell in sets.
The shows I do are between $100 and $550. I try to stay in the $350-400 range. I've found a couple of $150 shows that are great for me.
I do a couple of one day shows that are great, and a couple that are just a good way to earn several hundred dollars early in the season without putting in much effort. My first show if the year in April, a 1 day small show, will get me enough to buy my new canopy. The best show I've ever had was a one day show.
I do a couple of two day shows that would probably do very well as a one day show, as it puts more pressure on people to buy, and they just don't get the numbers to warrant 2 days.
Most of the 3 day shows I've done were not worth it. One of the days always seems to be a waste of time.
I tend to sell about the same at all the good shows I do. I have a number that I'm content with earning, but that number is different for everyone. It's a lower number than it was 5 years ago when the economy was stronger. I used to be able to sell at least one, often 2 or 3, big $250 jars at every show. Now I sell one or two of them a year, so I've got to make more small stuff to compensate.
I have a friend who sells 3x as much as I do at every show, but our work is very different, and she has to pay a couple of assistants, too. I have one show that I sell well at every year, but none of the other potters I talk to ever do very well at it. There's a lot of turnover amongst the potters every year at that show. I can't explain it.
It's a tough gig, and you just have to figure out what works for you. There are a lot of shows I won't do because my work is too expensive for them. There are others I won't do because the show is too expensive for me.
Whatever shows you do, make sure your canopy and displays are up to the task. Weather is a killer. I've always used a pop-up canopy, and it has served me well through some really nasty weather, but I put a lot of weight on the corners, and have stabilizer bars on all sides. It only ever got crumpled once, and the Trimline and Light Dome canopies went down, too- nothing can handle 80mph winds very well. I'm getting a new one this year that will be much beefier, but still a pop-up.