I'm no stove expert, but I can talk from my own
experience of using woodstoves for close to 40 years.
The "hot plate" or "pan ring" on a woodstove is designed to be removed and the pot is placed over the hole for cooking. My grandmother would alternate between placing the cook pot over the opening versus atop the plate versus atop a cooking ring she placed on the plate, all depending upon how much heat she wanted for cooking. Her woodstove had different sized plates to not only accommodate different sized pots but to also limit the exposure to the hot flames & gases. It also had one "burner" where the plate was a series of rings so the size of the hole was adjustable. Many steel stoves don't have the removable plates since the stove surface heats up much more quickly than a cast iron one. So there's not as much of a need to get the pot bottom closer to the heat while waiting for the cast iron to heat up. But I've seen heavy gauge steel stoves with cooking plates.
Does one need to stay within the designated ring? No. I'll move a pot to the corner when I want it to cook slower. The corners are usually cooler. That's where the saying "put it on the back burner" or "on the back of the stove" came from. It was cooler there. Things cooked slower.
Cast iron stoves heat up slower and also cool down slower than steel stoves. Starting out a cast iron stove with a roaring fire can heat it up too quickly, thus causing a crack. I've never had a stove crack from putting a room temperature pot into it, but I've been warned not to take a pot from the refrigerator and place it onto a hot stove. Also, I was taught not to put pots on until the stove heated up some. No cold pots atop a freshly started stove. Give the metal a chance to heat and expand first.
Stoves can be cracked not only by firing them too quickly or too hot, but also by adding a frozen log. My neighbor used frozen logs that he stored outside on his porch until the time he threw one in that was crusted in ice and CRACK. Luckily he was able to replace the part that cracked. I heard of another neighbor who had over fired his stove and it was glowing cherry red. He threw a pot of water on it, cracking the stove.
Those bricks inside the stove are not for heat retention, but rather, to protect the metal from intense heat. Intense heat can weaken the metal. Never run a stove designed to use firebricks without the bricks installed. Otherwise the stove can literally be burned out over time. If the salesman tells you that the bricks are for heat retention, then he's not familiar with woodstoves. I'd be really wary.
I'm running a Morso Squirrel in my home right now. It's a small stove but I can fit two pots on it. It's a cast iron one. I would have preferred a good steel box, but they aren't available here and the shipping costs to bring one I were way too high.