RE: Wall tent stove question.
Biggest reason for the damper, IMHO, is to control burn rate. If you go when it's cold, not much chance of getting the tent too hot at night. But it does greatly enhance your ability to keep a fire until the wee hours. For our bunch, means you can load it up at night and still have some in the morning. Only important to me the first couple of days before season starts. After that, I am up and out in a cold tent and have no need for fire.
The spark arrestor mentioned earlier goes on the top of the pipe. Good idea if you want to save your tent and the forest around you.
And I would be careful with using coal. Depending on the "amount" of fire you have and the stove you are using, it can burn hot enough to burn through your stove. We have stoves made out of 1/8 steel plate with grates made from 5/8 sucker rods and I still wouldn't use coal in them for fear of warping. Just my .02 worth.
Choke down both the chimney and door side dampers and you can have a fire to roaring in no time in the morning.....
Mmm...I can smell smoke!!! Makes my neck swell and my tarsal glands weep a might!!!