Doing this alone and just because you want to is lame anyway. And if you are scared that it's fly away and drop down then start a fire. Then it most likely fall down cuz it burned off and if some way it starts to fall down while still burning the flame will go off way before it hits the ground
Aight, time to start another forest fire. Seriously though, I don't recommend doing this but you can. Just make sure it doesn't float to far away and make sure to put it out. Though it doesn't have the same effect as it floats away mysteriously in the starry night sky, it's better than burning something down.
Depends on where you do it and if the law there allows it ig. And if the area around where you do it is not very flammable then it's good. It's better to light it up on the roof of a high rise building or very high places cause it'll float up faster and if it starts burning then it'll take a long time before dropping. We do this few times a year and I've never seen a fireball dropping from the sky. Either it burns on the ground before floating or burns in the sky. The paper used to make it is super thin and burns in a flash.