I've made my own, and the first time i coulda gotten pretty hurt, and the 2nd time (a couple days ago) i put it into a pvc tube, and it went alot further than i thought it was. The way to make it so it doesnt burn as hot/slower is you add baking soda. The baking soda releases carbon dioxide when it is burned, and reduces the amount of oxygen therefore "limiting a reactant". The kno3 works as a oxidizer. I haven't taken ap chem yet (within the next 2 years) but yes the sugar burns very hot.
going back to my first experiment, i was stupid enough to use a glass jar to hold the liquid, but i didn't how how easily lightable it was. It doesnt light from the heat, but anything close to a spark lights it.
the online formula is normally 60/40 pno3 to sugar (by volume). i've read that if you add sulfur it'll make more smoke or something, but i've tried both, and havent done enough of it to see the difference. the more sugar you put the more smoke, and more kno3 the faster reaction. I've tried doing the equation for it, and i found the weights for a complete reaction, but i forgot it. i think it was like 3/1 sugar to kno3. One of the products (from my equation) was KNO, which i'm pretty sure is poisonous in some way or another.
For colored smoke, you can add rit dye or powdered dye for dying t-shirts. I've only tried this once so far, but you need to add the dye after your done heating it or the dye will evaporate while your cooking it, and it wont color your smoke.
If your going to do this, it makes alot more smoke when you melt it together, because it probably makes the stuff more concentrated with less air pockets.
And don't use anything glass, or anything that will break under pressure. I chose pvc because it will melt instead of shatter, and imo its somewhat safer.
the smoke doesn't rise more than 50 ft visibly. My yard is surrounded by trees, and it doesn't really rise more than the trees.
Oh and if you are going to do this, Be Safe. Keep a couple containers of baking soda around, or a fire extinguisher. I chose baking soda, because it works pretty well, and you can get it cheap.